Journal Articles
Years 2011 – 2024
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20.
Long Luo, Liang Zhang, Graeme Henkelman, Richard M Crooks, "Unusual Activity Trend for CO Oxidation on Pd x Au 140– x @Pt Core@Shell Nanoparticle Electrocatalysts", The Journal of Physical Chemistry Letters, 6, 13, 2015, 2562-2568.
@article{Luo2015,
title = {Unusual Activity Trend for CO Oxidation on Pd x Au 140– x @Pt Core@Shell Nanoparticle Electrocatalysts},
author = {Long Luo and Liang Zhang and Graeme Henkelman and Richard M Crooks},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/acs.jpclett.5b00985.pdf, PDF},
doi = {10.1021/acs.jpclett.5b00985},
issn = {1948-7185},
year = {2015},
date = {2015-07-01},
journal = {The Journal of Physical Chemistry Letters},
volume = {6},
number = {13},
pages = {2562--2568},
abstract = {A theoretical and experimental study of the electrocatalytic oxidation of CO on PdxAu140-x@Pt dendrimer-encapsulated nanoparticle (DEN) catalysts is presented. These nanoparticles are comprised of a core having an average of 140 atoms and a Pt monolayer shell. The CO oxidation activity trend exhibits an unusual koppa shape as the number of Pd atoms in the core is varied from 0 to 140. Calculations based on density functional theory suggest that the koppa-shaped trend is driven primarily by structural changes that affect the CO binding energy on the surface. Specifically, a pure Au core leads to deformation of the Pt shell and a compression of the Pt lattice. In contrast, Pd, from the pure Pd cores, tends to segregate on the DEN surface, forming an inverted configuration having Pt within the core and Pd in the shell. With a small addition of Au, however, the alloy PdAu cores stabilize the core@shell structures by preventing Au and Pd from escaping to the particle surface.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A theoretical and experimental study of the electrocatalytic oxidation of CO on PdxAu140-x@Pt dendrimer-encapsulated nanoparticle (DEN) catalysts is presented. These nanoparticles are comprised of a core having an average of 140 atoms and a Pt monolayer shell. The CO oxidation activity trend exhibits an unusual koppa shape as the number of Pd atoms in the core is varied from 0 to 140. Calculations based on density functional theory suggest that the koppa-shaped trend is driven primarily by structural changes that affect the CO binding energy on the surface. Specifically, a pure Au core leads to deformation of the Pt shell and a compression of the Pt lattice. In contrast, Pd, from the pure Pd cores, tends to segregate on the DEN surface, forming an inverted configuration having Pt within the core and Pd in the shell. With a small addition of Au, however, the alloy PdAu cores stabilize the core@shell structures by preventing Au and Pd from escaping to the particle surface.
19.
Rachel M Anderson, David F Yancey, Liang Zhang, Samuel T Chill, Graeme Henkelman, Richard M Crooks, "A Theoretical and Experimental Approach for Correlating Nanoparticle Structure and Electrocatalytic Activity", Accounts of Chemical Research, 48, 5, 2015, 1351-1357.
@article{Anderson2015,
title = {A Theoretical and Experimental Approach for Correlating Nanoparticle Structure and Electrocatalytic Activity},
author = {Rachel M Anderson and David F Yancey and Liang Zhang and Samuel T Chill and Graeme Henkelman and Richard M Crooks},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/acs.accounts.5b00125.pdf, PDF},
doi = {10.1021/acs.accounts.5b00125},
issn = {0001-4842},
year = {2015},
date = {2015-05-01},
journal = {Accounts of Chemical Research},
volume = {48},
number = {5},
pages = {1351--1357},
abstract = {ConspectusThe objective of the research described in this Account is the development of high-throughput computational-based screening methods for discovery of catalyst candidates and subsequent experimental validation using appropriate catalytic nanoparticles. Dendrimer-encapsulated nanoparticles (DENs), which are well-defined 1-2 nm diameter metal nanoparticles, fulfill the role of model electrocatalysts.Effective comparison of theory and experiment requires that the theoretical and experimental models map onto one another perfectly. We use novel synthetic methods, advanced characterization techniques, and density functional theory (DFT) calculations to approach this ideal. For example, well-defined core@shell DENs can be synthesized by electrochemical underpotential deposition (UPD), and the observed deposition potentials can be compared to those calculated by DFT. Theory is also used to learn more about structure than can be determined by analytical characterization alone. For example, density functional theory molecular dynamics (DFT-MD) was used to show that the core@shell configuration of Au@Pt DENs undergoes a surface reconstruction that dramatically affects its electrocatalytic properties. A separate Pd@Pt DENs study also revealed reorganization, in this case a core-shell inversion to a Pt@Pd structure. Understanding these types of structural changes is critical to building correlations between structure and catalytic function.Indeed, the second principal focus of the work described here is correlating structure and catalytic function through the combined use of theory and experiment. For example, the Au@Pt DENs system described earlier is used for the oxygen reduction reaction (ORR) as well as for the electro-oxidation of formic acid. The surface reorganization predicted by theory enhances our understanding of the catalytic measurements. In the case of formic acid oxidation, the deformed nanoparticle structure leads to reduced CO binding energy and therefore improved oxidation activity. The final catalytic study we present is an instance of theory correctly predicting (in advance of the experiments) the structure of an effective DEN electrocatalyst. Specifically, DFT was used to determine the optimal composition of the alloy-core in AuPd@Pt DENs for the ORR. This prediction was subsequently confirmed experimentally. This study highlights the major theme of our research: the progression of using theory to rationalize experimental results to the more advanced goal of using theory to predict catalyst function a priori. We still have a long way to go before theory will be the principal means of catalyst discovery, but this Account begins to shed some light on the path that may lead in that direction.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
ConspectusThe objective of the research described in this Account is the development of high-throughput computational-based screening methods for discovery of catalyst candidates and subsequent experimental validation using appropriate catalytic nanoparticles. Dendrimer-encapsulated nanoparticles (DENs), which are well-defined 1-2 nm diameter metal nanoparticles, fulfill the role of model electrocatalysts.Effective comparison of theory and experiment requires that the theoretical and experimental models map onto one another perfectly. We use novel synthetic methods, advanced characterization techniques, and density functional theory (DFT) calculations to approach this ideal. For example, well-defined core@shell DENs can be synthesized by electrochemical underpotential deposition (UPD), and the observed deposition potentials can be compared to those calculated by DFT. Theory is also used to learn more about structure than can be determined by analytical characterization alone. For example, density functional theory molecular dynamics (DFT-MD) was used to show that the core@shell configuration of Au@Pt DENs undergoes a surface reconstruction that dramatically affects its electrocatalytic properties. A separate Pd@Pt DENs study also revealed reorganization, in this case a core-shell inversion to a Pt@Pd structure. Understanding these types of structural changes is critical to building correlations between structure and catalytic function.Indeed, the second principal focus of the work described here is correlating structure and catalytic function through the combined use of theory and experiment. For example, the Au@Pt DENs system described earlier is used for the oxygen reduction reaction (ORR) as well as for the electro-oxidation of formic acid. The surface reorganization predicted by theory enhances our understanding of the catalytic measurements. In the case of formic acid oxidation, the deformed nanoparticle structure leads to reduced CO binding energy and therefore improved oxidation activity. The final catalytic study we present is an instance of theory correctly predicting (in advance of the experiments) the structure of an effective DEN electrocatalyst. Specifically, DFT was used to determine the optimal composition of the alloy-core in AuPd@Pt DENs for the ORR. This prediction was subsequently confirmed experimentally. This study highlights the major theme of our research: the progression of using theory to rationalize experimental results to the more advanced goal of using theory to predict catalyst function a priori. We still have a long way to go before theory will be the principal means of catalyst discovery, but this Account begins to shed some light on the path that may lead in that direction.
18.
Wen-Yueh Yu, Liang Zhang, Gregory M Mullen, Graeme Henkelman, Buddie C Mullins, "Oxygen Activation and Reaction on Pd–Au Bimetallic Surfaces", The Journal of Physical Chemistry C, 119, 21, 2015, 11754-11762.
@article{Yu2015,
title = {Oxygen Activation and Reaction on Pd–Au Bimetallic Surfaces},
author = {Wen-Yueh Yu and Liang Zhang and Gregory M Mullen and Graeme Henkelman and Buddie C Mullins},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/acs.jpcc.5b02970.pdf, PDF},
doi = {10.1021/acs.jpcc.5b02970},
issn = {1932-7447},
year = {2015},
date = {2015-05-01},
journal = {The Journal of Physical Chemistry C},
volume = {119},
number = {21},
pages = {11754--11762},
abstract = {We report electrocatalytic oxidation of formic acid using monometallic and bimetallic dendrimer-encapsulated nanoparticles (DENs). The results indicate that the Au147@Pt DENs exhibit better electrocatalytic activity and low CO formation. Theoretical calculations attribute the observed activity to the deformation of nanoparticle structure, slow dehydration of formic acid, and weak binding of CO on Au147@Pt surface. Subsequent experiments confirmed the theoretical predictions. textcopyright 2013 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report electrocatalytic oxidation of formic acid using monometallic and bimetallic dendrimer-encapsulated nanoparticles (DENs). The results indicate that the Au147@Pt DENs exhibit better electrocatalytic activity and low CO formation. Theoretical calculations attribute the observed activity to the deformation of nanoparticle structure, slow dehydration of formic acid, and weak binding of CO on Au147@Pt surface. Subsequent experiments confirmed the theoretical predictions. textcopyright 2013 American Chemical Society.
17.
Liang Zhang, Graeme Henkelman, "Computational Design of Alloy-Core@Shell Metal Nanoparticle Catalysts", ACS Catalysis, 5, 2, 2015, 655-660.
@article{Zhang2015b,
title = {Computational Design of Alloy-Core@Shell Metal Nanoparticle Catalysts},
author = {Liang Zhang and Graeme Henkelman},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/cs501176b.pdf, PDF},
doi = {10.1021/cs501176b},
issn = {2155-5435},
year = {2015},
date = {2015-02-01},
urldate = {2015-02-01},
journal = {ACS Catalysis},
volume = {5},
number = {2},
pages = {655--660},
abstract = {The alloy-core@shell nanoparticle structure combines the advantages of a robust noble-metal shell and a tunable alloy-core composition. In this study we demonstrate a set of linear correlations between the binding of adsorbates to the shell and the alloy-core composition, which are general across a range of nanoparticle compositions, size, and adsorbate molecules. This systematic tunability allows for a simple approach to the design of such catalysts. Calculations of candidate structures for the hydrogen evolution reaction predict a high activity for the PtRu@Pd structure, in good agreement with what has been reported previously. Calculations of alloy-core@Pt 140-atom nanoparticles reveal new candidate structures for CO oxidation at high temperature, including Au0.65Pd0.35@Pt and Au0.73Pt0.27@Pt, which are predicted to have reaction rates 200 times higher than that of Pt(111).},
keywords = {},
pubstate = {published},
tppubtype = {article}
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The alloy-core@shell nanoparticle structure combines the advantages of a robust noble-metal shell and a tunable alloy-core composition. In this study we demonstrate a set of linear correlations between the binding of adsorbates to the shell and the alloy-core composition, which are general across a range of nanoparticle compositions, size, and adsorbate molecules. This systematic tunability allows for a simple approach to the design of such catalysts. Calculations of candidate structures for the hydrogen evolution reaction predict a high activity for the PtRu@Pd structure, in good agreement with what has been reported previously. Calculations of alloy-core@Pt 140-atom nanoparticles reveal new candidate structures for CO oxidation at high temperature, including Au0.65Pd0.35@Pt and Au0.73Pt0.27@Pt, which are predicted to have reaction rates 200 times higher than that of Pt(111).
16.
Wen-Yueh Yu, Liang Zhang, Gregory M Mullen, Edward J Evans, Graeme Henkelman, Buddie C Mullins, "Effect of annealing in oxygen on alloy structures of Pd–Au bimetallic model catalysts", Physical Chemistry Chemical Physics, 17, 32, 2015, 20588-20596.
@article{Yu2015a,
title = {Effect of annealing in oxygen on alloy structures of Pd–Au bimetallic model catalysts},
author = {Wen-Yueh Yu and Liang Zhang and Gregory M Mullen and Edward J Evans and Graeme Henkelman and Buddie C Mullins},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/c5cp03515e.pdf, PDF},
doi = {10.1039/C5CP03515E},
issn = {1463-9076},
year = {2015},
date = {2015-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {17},
number = {32},
pages = {20588--20596},
abstract = {It has been reported that Pd–Au bimetallic catalysts display improved catalytic performance after adequate calcination. In this study, a model catalyst study was conducted to investigate the effects of annealing in oxygen on the surface structures of Pd–Au alloys by comparing the physicochemical properties of Pd/Au(111) surfaces that were annealed in ultrahigh vacuum (UHV) versus in an oxygen ambient. Auger electron spectroscopy (AES) and Basin hopping simulations reveal that the presence of oxygen can inhibit the diffusion of surface Pd atoms into the subsurface of the Au(111) sample. Reflection–absorption infrared spectroscopy using CO as a probe molecule (CO-RAIRS) and King–Wells measurements of O2 uptake suggest that surfaces annealed in an oxygen ambient possess more contiguous Pd sites than surfaces annealed under UHV conditions. The oxygen-annealed Pd/Au(111) surface exhibited a higher activity for CO oxidation in reactive molecular beam scattering (RMBS) experiments. This enhanced activity likely results from the higher oxygen uptake and relatively facile dissociation of oxygen admolecules due to stronger adsorbate–surface interactions as suggested by temperature-programmed desorption (TPD) measurements. These observations provide fundamental insights into the surface phenomena of Pd–Au alloys, which may prove beneficial in the design of future Pd–Au catalysts.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
It has been reported that Pd–Au bimetallic catalysts display improved catalytic performance after adequate calcination. In this study, a model catalyst study was conducted to investigate the effects of annealing in oxygen on the surface structures of Pd–Au alloys by comparing the physicochemical properties of Pd/Au(111) surfaces that were annealed in ultrahigh vacuum (UHV) versus in an oxygen ambient. Auger electron spectroscopy (AES) and Basin hopping simulations reveal that the presence of oxygen can inhibit the diffusion of surface Pd atoms into the subsurface of the Au(111) sample. Reflection–absorption infrared spectroscopy using CO as a probe molecule (CO-RAIRS) and King–Wells measurements of O2 uptake suggest that surfaces annealed in an oxygen ambient possess more contiguous Pd sites than surfaces annealed under UHV conditions. The oxygen-annealed Pd/Au(111) surface exhibited a higher activity for CO oxidation in reactive molecular beam scattering (RMBS) experiments. This enhanced activity likely results from the higher oxygen uptake and relatively facile dissociation of oxygen admolecules due to stronger adsorbate–surface interactions as suggested by temperature-programmed desorption (TPD) measurements. These observations provide fundamental insights into the surface phenomena of Pd–Au alloys, which may prove beneficial in the design of future Pd–Au catalysts.
15.
Gregory M Mullen, Liang Zhang, Edward J Evans, Ting Yan, Graeme Henkelman, Buddie C Mullins, "Control of selectivity in allylic alcohol oxidation on gold surfaces: the role of oxygen adatoms and hydroxyl species", Physical Chemistry Chemical Physics, 17, 6, 2015, 4730-4738.
@article{Mullen2015,
title = {Control of selectivity in allylic alcohol oxidation on gold surfaces: the role of oxygen adatoms and hydroxyl species},
author = {Gregory M Mullen and Liang Zhang and Edward J Evans and Ting Yan and Graeme Henkelman and Buddie C Mullins},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/c4cp04739g.pdf, PDF},
doi = {10.1039/C4CP04739G},
issn = {1463-9076},
year = {2015},
date = {2015-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {17},
number = {6},
pages = {4730--4738},
abstract = {Gold catalysts display high activity and good selectivity for partial oxidation of a number of alcohol species. In this work, we discuss the effects of oxygen adatoms and surface hydroxyls on the selectivity for oxidation of allylic alcohols (allyl alcohol and crotyl alcohol) on gold surfaces. Utilizing temperature programmed desorption (TPD), reactive molecular beam scattering (RMBS), and density functional theory (DFT) techniques, we provide evidence to suggest that the selectivity displayed towards partial oxidation versus combustion pathways is dependent on the type of oxidant species present on the gold surface. TPD and RMBS results suggest that surface hydroxyls promote partial oxidation of allylic alcohols to their corresponding aldehydes with very high selectivity, while oxygen adatoms promote both partial oxidation and combustion pathways. DFT calculations indicate that oxygen adatoms can react with acrolein to promote the formation of a bidentate surface intermediate, similar to structures that have been shown to decompose to generate combustion products over other transition metal surfaces. Surface hydroxyls do not readily promote such a process. Our results help explain phenomena observed in previous studies and may prove useful in the design of future catalysts for partial oxidation of alcohols.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gold catalysts display high activity and good selectivity for partial oxidation of a number of alcohol species. In this work, we discuss the effects of oxygen adatoms and surface hydroxyls on the selectivity for oxidation of allylic alcohols (allyl alcohol and crotyl alcohol) on gold surfaces. Utilizing temperature programmed desorption (TPD), reactive molecular beam scattering (RMBS), and density functional theory (DFT) techniques, we provide evidence to suggest that the selectivity displayed towards partial oxidation versus combustion pathways is dependent on the type of oxidant species present on the gold surface. TPD and RMBS results suggest that surface hydroxyls promote partial oxidation of allylic alcohols to their corresponding aldehydes with very high selectivity, while oxygen adatoms promote both partial oxidation and combustion pathways. DFT calculations indicate that oxygen adatoms can react with acrolein to promote the formation of a bidentate surface intermediate, similar to structures that have been shown to decompose to generate combustion products over other transition metal surfaces. Surface hydroxyls do not readily promote such a process. Our results help explain phenomena observed in previous studies and may prove useful in the design of future catalysts for partial oxidation of alcohols.
14.
Stephany García, Liang Zhang, Graham W Piburn, Graeme Henkelman, Simon M Humphrey, "Microwave Synthesis of Classically Immiscible Rhodium–Silver and Rhodium–Gold Alloy Nanoparticles: Highly Active Hydrogenation Catalysts", ACS Nano, 8, 11, 2014, 11512-11521.
@article{Garcia2014,
title = {Microwave Synthesis of Classically Immiscible Rhodium–Silver and Rhodium–Gold Alloy Nanoparticles: Highly Active Hydrogenation Catalysts},
author = {Stephany García and Liang Zhang and Graham W Piburn and Graeme Henkelman and Simon M Humphrey},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/nn504746u.pdf, PDF},
doi = {10.1021/nn504746u},
issn = {1936-0851},
year = {2014},
date = {2014-11-01},
journal = {ACS Nano},
volume = {8},
number = {11},
pages = {11512--11521},
abstract = {Noble metal alloys are important in large-scale catalytic processes. Alloying facilitates fine-tuning of catalytic properties via synergistic interactions between metals. It also allows for dilution of scarce and expensive metals using comparatively earth-abundant metals. RhAg and RhAu are classically considered to be immiscible metals. We show here that stable RhM (M = Ag, Au) nanoparticles with randomly alloyed structures and broadly tunable Rh:M ratios can be prepared using a microwave-assisted method. The alloyed nanostructures with optimized Rh:M compositions are significantly more active as hydrogenation catalysts than Rh itself: Rh is more dilute and more reactive when alloyed with Ag or Au, even though the latter are both catalytically inactive for hydrogenation. Theoretical modeling predicts that the observed catalytic enhancement is due to few-atom surface ensemble effects in which the overall reaction energy profile for alkene hydrogenation is optimized due to RhM d-band intermixing.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Noble metal alloys are important in large-scale catalytic processes. Alloying facilitates fine-tuning of catalytic properties via synergistic interactions between metals. It also allows for dilution of scarce and expensive metals using comparatively earth-abundant metals. RhAg and RhAu are classically considered to be immiscible metals. We show here that stable RhM (M = Ag, Au) nanoparticles with randomly alloyed structures and broadly tunable Rh:M ratios can be prepared using a microwave-assisted method. The alloyed nanostructures with optimized Rh:M compositions are significantly more active as hydrogenation catalysts than Rh itself: Rh is more dilute and more reactive when alloyed with Ag or Au, even though the latter are both catalytically inactive for hydrogenation. Theoretical modeling predicts that the observed catalytic enhancement is due to few-atom surface ensemble effects in which the overall reaction energy profile for alkene hydrogenation is optimized due to RhM d-band intermixing.
13.
Samuel T Chill, Matthew Welborn, Rye Terrell, Liang Zhang, Jean-Claude Berthet, Andreas Pedersen, Hannes Jónsson, Graeme Henkelman, "EON: software for long time simulations of atomic scale systems", Modelling and Simulation in Materials Science and Engineering, 22, 5, 2014, 055002.
@article{Chill2014,
title = {EON: software for long time simulations of atomic scale systems},
author = {Samuel T Chill and Matthew Welborn and Rye Terrell and Liang Zhang and Jean-Claude Berthet and Andreas Pedersen and Hannes Jónsson and Graeme Henkelman},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/Chill_2014_Modelling_Simul._Mater._Sci._Eng._22_055002.pdf, PDF},
doi = {10.1088/0965-0393/22/5/055002},
issn = {0965-0393},
year = {2014},
date = {2014-07-01},
journal = {Modelling and Simulation in Materials Science and Engineering},
volume = {22},
number = {5},
pages = {055002},
abstract = {The EON software is designed for simulations of the state-to-state evolution of atomic scale systems over timescales greatly exceeding that of direct classical dynamics. States are defined as collections of atomic configurations from which a minimization of the potential energy gives the same inherent structure. The time evolution is assumed to be governed by rare events, where transitions between states are uncorrelated and infrequent compared with the timescale of atomic vibrations. Several methods for calculating the state-to-state evolution have been implemented in EON, including parallel replica dynamics, hyperdynamics and adaptive kinetic Monte Carlo. Global optimization methods, including simulated annealing, basin hopping and minima hopping are also implemented. The software has a client/server architecture where the computationally intensive evaluations of the interatomic interactions are calculated on the client-side and the state-to-state evolution is managed by the server. The client supports optimization for different computer architectures to maximize computational efficiency. The server is written in Python so that developers have access to the high-level functionality without delving into the computationally intensive components. Communication between the server and clients is abstracted so that calculations can be deployed on a single machine, clusters using a queuing system, large parallel computers using a message passing interface, or within a distributed computing environment. A generic interface to the evaluation of the interatomic interactions is defined so that empirical potentials, such as in LAMMPS, and density functional theory as implemented in VASP and GPAW can be used interchangeably. Examples are given to demonstrate the range of systems that can be modeled, including surface diffusion and island ripening of adsorbed atoms on metal surfaces, molecular diffusion on the surface of ice and global structural optimization of nanoparticles. textcopyright 2014 IOP Publishing Ltd.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The EON software is designed for simulations of the state-to-state evolution of atomic scale systems over timescales greatly exceeding that of direct classical dynamics. States are defined as collections of atomic configurations from which a minimization of the potential energy gives the same inherent structure. The time evolution is assumed to be governed by rare events, where transitions between states are uncorrelated and infrequent compared with the timescale of atomic vibrations. Several methods for calculating the state-to-state evolution have been implemented in EON, including parallel replica dynamics, hyperdynamics and adaptive kinetic Monte Carlo. Global optimization methods, including simulated annealing, basin hopping and minima hopping are also implemented. The software has a client/server architecture where the computationally intensive evaluations of the interatomic interactions are calculated on the client-side and the state-to-state evolution is managed by the server. The client supports optimization for different computer architectures to maximize computational efficiency. The server is written in Python so that developers have access to the high-level functionality without delving into the computationally intensive components. Communication between the server and clients is abstracted so that calculations can be deployed on a single machine, clusters using a queuing system, large parallel computers using a message passing interface, or within a distributed computing environment. A generic interface to the evaluation of the interatomic interactions is defined so that empirical potentials, such as in LAMMPS, and density functional theory as implemented in VASP and GPAW can be used interchangeably. Examples are given to demonstrate the range of systems that can be modeled, including surface diffusion and island ripening of adsorbed atoms on metal surfaces, molecular diffusion on the surface of ice and global structural optimization of nanoparticles. textcopyright 2014 IOP Publishing Ltd.
12.
Gregory M Mullen, Liang Zhang, Edward J Evans, Ting Yan, Graeme Henkelman, Buddie C Mullins, "Oxygen and Hydroxyl Species Induce Multiple Reaction Pathways for the Partial Oxidation of Allyl Alcohol on Gold", Journal of the American Chemical Society, 136, 17, 2014, 6489-6498.
@article{Mullen2014,
title = {Oxygen and Hydroxyl Species Induce Multiple Reaction Pathways for the Partial Oxidation of Allyl Alcohol on Gold},
author = {Gregory M Mullen and Liang Zhang and Edward J Evans and Ting Yan and Graeme Henkelman and Buddie C Mullins},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/ja502347d.pdf, PDF},
doi = {10.1021/ja502347d},
issn = {0002-7863},
year = {2014},
date = {2014-04-01},
journal = {Journal of the American Chemical Society},
volume = {136},
number = {17},
pages = {6489--6498},
abstract = {Partial oxidation of alcohols is a topic of great interest in the field of gold catalysis. In this work, we provide evidence that the partial oxidation of allyl alcohol to its corresponding aldehyde, acrolein, over oxygen-precovered gold surfaces occurs via multiple reaction pathways. Utilizing temperature-programmed desorption (TPD) with isotopically labeled water and oxygen species, reactive molecular beam scattering, and density functional theory (DFT) calculations, we demonstrate that the reaction mechanism for allyl alcohol oxidation is influenced by the relative proportions of atomic oxygen and hydroxyl species on the gold surface. Both atomic oxygen and hydroxyl species are shown to be active for allyl alcohol oxidation, but each displays a different pathway of oxidation, as indicated by TPD measurements and DFT calculations. The hydroxyl hydrogen of allyl alcohol is readily abstracted by either oxygen adatoms or adsorbed hydroxyl species on the gold surface to generate a surface-bound allyloxide intermediate, which then undergoes $alpha$-dehydrogenation via interaction with an oxygen adatom or surface hydroxyl species to generate acrolein. Mediation of a second allyloxide with the hydroxyl species lowers the activation barrier for the $alpha$-dehydrogenation process. A third pathway exists in which two hydroxyl species recombine to generate water and an oxygen adatom, which subsequently dehydrogenates allyloxide. This work may aid in the understanding of oxidative catalysis over gold and the effect of water therein. textcopyright 2014 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Partial oxidation of alcohols is a topic of great interest in the field of gold catalysis. In this work, we provide evidence that the partial oxidation of allyl alcohol to its corresponding aldehyde, acrolein, over oxygen-precovered gold surfaces occurs via multiple reaction pathways. Utilizing temperature-programmed desorption (TPD) with isotopically labeled water and oxygen species, reactive molecular beam scattering, and density functional theory (DFT) calculations, we demonstrate that the reaction mechanism for allyl alcohol oxidation is influenced by the relative proportions of atomic oxygen and hydroxyl species on the gold surface. Both atomic oxygen and hydroxyl species are shown to be active for allyl alcohol oxidation, but each displays a different pathway of oxidation, as indicated by TPD measurements and DFT calculations. The hydroxyl hydrogen of allyl alcohol is readily abstracted by either oxygen adatoms or adsorbed hydroxyl species on the gold surface to generate a surface-bound allyloxide intermediate, which then undergoes $alpha$-dehydrogenation via interaction with an oxygen adatom or surface hydroxyl species to generate acrolein. Mediation of a second allyloxide with the hydroxyl species lowers the activation barrier for the $alpha$-dehydrogenation process. A third pathway exists in which two hydroxyl species recombine to generate water and an oxygen adatom, which subsequently dehydrogenates allyloxide. This work may aid in the understanding of oxidative catalysis over gold and the effect of water therein. textcopyright 2014 American Chemical Society.
11.
Liang Zhang, Ravikumar Iyyamperumal, David F Yancey, Richard M Crooks, Graeme Henkelman, "Design of Pt-Shell Nanoparticles with Alloy Cores for the Oxygen Reduction Reaction", ACS Nano, 7, 10, 2013, 9168-9172.
@article{Zhang2013a,
title = {Design of Pt-Shell Nanoparticles with Alloy Cores for the Oxygen Reduction Reaction},
author = {Liang Zhang and Ravikumar Iyyamperumal and David F Yancey and Richard M Crooks and Graeme Henkelman},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/nn403788a.pdf, PDF},
doi = {10.1021/nn403788a},
issn = {1936-0851},
year = {2013},
date = {2013-10-01},
journal = {ACS Nano},
volume = {7},
number = {10},
pages = {9168--9172},
abstract = {We report that the oxygen binding energy of alloy-core@Pt nanoparticles can be linearly tuned by varying the alloy-core composition. Using this tuning mechanism, we are able to predict optimal compositions for different alloy-core@Pt nanoparticles. Subsequent electrochemical measurements of ORR activities of AuPd@Pt dendrimer-encapsulated nanoparticles (DENs) are in a good agreement with the theoretical prediction that the peak of activity is achieved for a 28% Au/72% Pd alloy core supporting a Pt shell. Importantly, these findings represent an unusual case of first-principles theory leading to nearly perfect agreement with experimental results. textcopyright 2013 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report that the oxygen binding energy of alloy-core@Pt nanoparticles can be linearly tuned by varying the alloy-core composition. Using this tuning mechanism, we are able to predict optimal compositions for different alloy-core@Pt nanoparticles. Subsequent electrochemical measurements of ORR activities of AuPd@Pt dendrimer-encapsulated nanoparticles (DENs) are in a good agreement with the theoretical prediction that the peak of activity is achieved for a 28% Au/72% Pd alloy core supporting a Pt shell. Importantly, these findings represent an unusual case of first-principles theory leading to nearly perfect agreement with experimental results. textcopyright 2013 American Chemical Society.
10.
Rachel M Anderson, Liang Zhang, James A Loussaert, Anatoly I Frenkel, Graeme Henkelman, Richard M Crooks, "An Experimental and Theoretical Investigation of the Inversion of Pd@Pt Core@Shell Dendrimer-Encapsulated Nanoparticles", ACS Nano, 7, 10, 2013, 9345-9353.
@article{Anderson2013,
title = {An Experimental and Theoretical Investigation of the Inversion of Pd@Pt Core@Shell Dendrimer-Encapsulated Nanoparticles},
author = {Rachel M Anderson and Liang Zhang and James A Loussaert and Anatoly I Frenkel and Graeme Henkelman and Richard M Crooks},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/nn4040348.pdf, PDF},
doi = {10.1021/nn4040348},
issn = {1936-0851},
year = {2013},
date = {2013-10-01},
journal = {ACS Nano},
volume = {7},
number = {10},
pages = {9345--9353},
abstract = {Bimetallic PdPt dendrimer-encapsulated nanoparticles (DENs) having sizes of about 2 nm were synthesized by a homogeneous route that involved (1) formation of a Pd core, (2) deposition of a Cu shell onto the Pd core in the presence of H2 gas, and (3) galvanic exchange of Pt for the Cu shell. Under these conditions, a Pd@Pt core@shell DEN is anticipated, but detailed characterization by in-situ extended X-ray absorption fine structure (EXAFS) spectroscopy and other analytical methods indicate that the metals invert to yield a Pt-rich core with primarily Pd in the shell. The experimental findings correlate well with density functional theoretical (DFT) calculations. Theory suggests that the increased disorder associated with textless∼2 nm diameter nanoparticles, along with the relatively large number of edge and corner sites, drives the structural rearrangement. This type of rearrangement is not observed on larger nanoparticles or in bulk metals. textcopyright 2013 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Bimetallic PdPt dendrimer-encapsulated nanoparticles (DENs) having sizes of about 2 nm were synthesized by a homogeneous route that involved (1) formation of a Pd core, (2) deposition of a Cu shell onto the Pd core in the presence of H2 gas, and (3) galvanic exchange of Pt for the Cu shell. Under these conditions, a Pd@Pt core@shell DEN is anticipated, but detailed characterization by in-situ extended X-ray absorption fine structure (EXAFS) spectroscopy and other analytical methods indicate that the metals invert to yield a Pt-rich core with primarily Pd in the shell. The experimental findings correlate well with density functional theoretical (DFT) calculations. Theory suggests that the increased disorder associated with textless∼2 nm diameter nanoparticles, along with the relatively large number of edge and corner sites, drives the structural rearrangement. This type of rearrangement is not observed on larger nanoparticles or in bulk metals. textcopyright 2013 American Chemical Society.
9.
Liang Zhang, Hyun You Kim, Graeme Henkelman, "CO Oxidation at the Au–Cu Interface of Bimetallic Nanoclusters Supported on CeO 2 (111)", The Journal of Physical Chemistry Letters, 4, 17, 2013, 2943-2947.
@article{Zhang2013b,
title = {CO Oxidation at the Au–Cu Interface of Bimetallic Nanoclusters Supported on CeO 2 (111)},
author = {Liang Zhang and Hyun You Kim and Graeme Henkelman},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/jz401524d.pdf, PDF},
doi = {10.1021/jz401524d},
issn = {1948-7185},
year = {2013},
date = {2013-09-01},
journal = {The Journal of Physical Chemistry Letters},
volume = {4},
number = {17},
pages = {2943--2947},
abstract = {DFT+U calculations of the structure of CeO2(111)-supported Au-based bimetallic nanoclusters (NCs) show that a strong support-metal interaction induces a preferential segregation of the more reactive element to the NC-CeO2 perimeter, generating an interface with the Au component. We studied several Au -based bimetallic NCs (Au-X, X: Ag, Cu, Pd, Pt, Rh, and Ru) and found that (Au-Cu)/CeO2 is optimal for catalyzing CO oxidation via a bifunctional mechanism. O2 preferentially binds to the Cu-rich sites, whereas CO binds to the Au-rich sites. Engineering a two-component system in which the reactants do not compete for binding sites is the key to the high catalytic activity at the interface between the components. textcopyright 2013 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
DFT+U calculations of the structure of CeO2(111)-supported Au-based bimetallic nanoclusters (NCs) show that a strong support-metal interaction induces a preferential segregation of the more reactive element to the NC-CeO2 perimeter, generating an interface with the Au component. We studied several Au -based bimetallic NCs (Au-X, X: Ag, Cu, Pd, Pt, Rh, and Ru) and found that (Au-Cu)/CeO2 is optimal for catalyzing CO oxidation via a bifunctional mechanism. O2 preferentially binds to the Cu-rich sites, whereas CO binds to the Au-rich sites. Engineering a two-component system in which the reactants do not compete for binding sites is the key to the high catalytic activity at the interface between the components. textcopyright 2013 American Chemical Society.
8.
Ravikumar Iyyamperumal, Liang Zhang, Graeme Henkelman, Richard M Crooks, "Efficient Electrocatalytic Oxidation of Formic Acid Using Au@Pt Dendrimer-Encapsulated Nanoparticles", Journal of the American Chemical Society, 135, 15, 2013, 5521-5524.
@article{Iyyamperumal2013,
title = {Efficient Electrocatalytic Oxidation of Formic Acid Using Au@Pt Dendrimer-Encapsulated Nanoparticles},
author = {Ravikumar Iyyamperumal and Liang Zhang and Graeme Henkelman and Richard M Crooks},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/ja4010305.pdf, PDF},
doi = {10.1021/ja4010305},
issn = {0002-7863},
year = {2013},
date = {2013-04-01},
journal = {Journal of the American Chemical Society},
volume = {135},
number = {15},
pages = {5521--5524},
publisher = {American Chemical Society},
abstract = {We report electrocatalytic oxidation of formic acid using monometallic and bimetallic dendrimer-encapsulated nanoparticles (DENs). The results indicate that the Au147@Pt DENs exhibit better electrocatalytic activity and low CO formation. Theoretical calculations attribute the observed activity to the deformation of nanoparticle structure, slow dehydration of formic acid, and weak binding of CO on Au147@Pt surface. Subsequent experiments confirmed the theoretical predictions. textcopyright 2013 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report electrocatalytic oxidation of formic acid using monometallic and bimetallic dendrimer-encapsulated nanoparticles (DENs). The results indicate that the Au147@Pt DENs exhibit better electrocatalytic activity and low CO formation. Theoretical calculations attribute the observed activity to the deformation of nanoparticle structure, slow dehydration of formic acid, and weak binding of CO on Au147@Pt surface. Subsequent experiments confirmed the theoretical predictions. textcopyright 2013 American Chemical Society.
7.
David F Yancey, Samuel T Chill, Liang Zhang, Anatoly I Frenkel, Graeme Henkelman, Richard M Crooks, "A theoretical and experimental examination of systematic ligand-induced disorder in Au dendrimer-encapsulated nanoparticles", Chemical Science, 4, 7, 2013, 2912.
@article{Yancey2013,
title = {A theoretical and experimental examination of systematic ligand-induced disorder in Au dendrimer-encapsulated nanoparticles},
author = {David F Yancey and Samuel T Chill and Liang Zhang and Anatoly I Frenkel and Graeme Henkelman and Richard M Crooks},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/c3sc50614b.pdf, PDF},
doi = {10.1039/c3sc50614b},
issn = {2041-6520},
year = {2013},
date = {2013-01-01},
journal = {Chemical Science},
volume = {4},
number = {7},
pages = {2912},
abstract = {In this paper we present a new methodology for the analysis of 1-2 nm nanoparticles using extended X-ray absorption fine structure (EXAFS) spectroscopy. Different numbers of thiols were introduced onto the surfaces of dendrimer-encapsulated Au nanoparticles, consisting of an average of 147 atoms, to systematically tune the nanoparticle disorder. An analogous system was investigated using density functional theory molecular dynamics (DFT-MD) simulations to produce theoretical EXAFS signals that could be directly compared to the experimental results. Validation of the theoretical results by comparing to experiment allows us to infer previously unknown details of structure and dynamics of the nanoparticles. Additionally, the structural information that is learned from theoretical studies can be compared with traditional EXAFS fitting results to identify and rationalize any errors in the experimental fit. This study demonstrates that DFT-MD simulations accurately depict complex experimental systems in which we have control over nanoparticle disorder, and shows the advantages of using a combined experimental/theoretical approach over standard EXAFS fitting methodologies for determining the structural parameters of metallic nanoparticles. textcopyright 2013 Royal Society of Chemistry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper we present a new methodology for the analysis of 1-2 nm nanoparticles using extended X-ray absorption fine structure (EXAFS) spectroscopy. Different numbers of thiols were introduced onto the surfaces of dendrimer-encapsulated Au nanoparticles, consisting of an average of 147 atoms, to systematically tune the nanoparticle disorder. An analogous system was investigated using density functional theory molecular dynamics (DFT-MD) simulations to produce theoretical EXAFS signals that could be directly compared to the experimental results. Validation of the theoretical results by comparing to experiment allows us to infer previously unknown details of structure and dynamics of the nanoparticles. Additionally, the structural information that is learned from theoretical studies can be compared with traditional EXAFS fitting results to identify and rationalize any errors in the experimental fit. This study demonstrates that DFT-MD simulations accurately depict complex experimental systems in which we have control over nanoparticle disorder, and shows the advantages of using a combined experimental/theoretical approach over standard EXAFS fitting methodologies for determining the structural parameters of metallic nanoparticles. textcopyright 2013 Royal Society of Chemistry.
6.
Liang Zhang, Graeme Henkelman, "Tuning the Oxygen Reduction Activity of Pd Shell Nanoparticles with Random Alloy Cores", The Journal of Physical Chemistry C, 116, 39, 2012, 20860-20865.
@article{Zhang2012,
title = {Tuning the Oxygen Reduction Activity of Pd Shell Nanoparticles with Random Alloy Cores},
author = {Liang Zhang and Graeme Henkelman},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/jp305367z.pdf, PDF},
doi = {10.1021/jp305367z},
issn = {1932-7447},
year = {2012},
date = {2012-10-01},
journal = {The Journal of Physical Chemistry C},
volume = {116},
number = {39},
pages = {20860--20865},
abstract = {Pd-based nanoparticles are promising candidates for non-Pt catalysts of the oxygen reduction reaction (ORR). Trends in ORR activity of Pd/Cu-alloy-core@Pd- shell nanoparticles are studied by calculating the oxygen binding energy on the Pd surface with different Cu compositions in the alloy core. Density functional theory calculations show that several properties of the nanoparticle surface, including the average oxygen binding energy, d-band center, and the net charge of Pd, are linearly related to the ratio of Cu in the core, demonstrating the capacity to tune ORR activity. Trends in oxygen binding of other core alloys are also studied and show similar linear trends with core composition, providing a design strategy for new ORR catalysts. textcopyright 2012 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Pd-based nanoparticles are promising candidates for non-Pt catalysts of the oxygen reduction reaction (ORR). Trends in ORR activity of Pd/Cu-alloy-core@Pd- shell nanoparticles are studied by calculating the oxygen binding energy on the Pd surface with different Cu compositions in the alloy core. Density functional theory calculations show that several properties of the nanoparticle surface, including the average oxygen binding energy, d-band center, and the net charge of Pd, are linearly related to the ratio of Cu in the core, demonstrating the capacity to tune ORR activity. Trends in oxygen binding of other core alloys are also studied and show similar linear trends with core composition, providing a design strategy for new ORR catalysts. textcopyright 2012 American Chemical Society.
5.
David F Yancey, Liang Zhang, Richard M Crooks, Graeme Henkelman, "Au@Pt dendrimer encapsulated nanoparticles as model electrocatalysts for comparison of experiment and theory", Chemical Science, 3, 4, 2012, 1033.
@article{Yancey2012,
title = {Au@Pt dendrimer encapsulated nanoparticles as model electrocatalysts for comparison of experiment and theory},
author = {David F Yancey and Liang Zhang and Richard M Crooks and Graeme Henkelman},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/c2sc00971d.pdf, PDF},
doi = {10.1039/c2sc00971d},
issn = {2041-6520},
year = {2012},
date = {2012-01-01},
journal = {Chemical Science},
volume = {3},
number = {4},
pages = {1033},
abstract = {In this paper we report the electrochemical synthesis of core@shell dendrimer-encapsulated nanoparticles (DENs) consisting of cores containing 147 Au atoms (Autextlessinftextgreater147textless/inftextgreater) and Pt shells having ∼54 or ∼102 atoms (Autextlessinftextgreater147textless/inftextgreater@Pttextlessinftextgreaterntextless/inftextgreater (n = 54 or 102)). The significance of this work arises from the correlation of the experimentally determined structural and electrocatalytic properties of these particles with density functional theory (DFT) calculations. Specifically, we describe an experimental and theoretical study of Pb underpotential deposition (UPD) on Autextlessinftextgreater147textless/inftextgreater DENs, the structure of both Autextlessinftextgreater147textless/inftextgreater@Pbtextlessinftextgreaterntextless/inftextgreater and Autextlessinftextgreater147textless/inftextgreater@Pt textlessinftextgreaterntextless/inftextgreater DENs, and the activity of these DENs for the oxygen reduction reaction (ORR). DFT calculations show that Pb binding is stronger on the (100) facets of Au as compared to (111), and the calculated deposition and stripping potentials are consistent with those measured experimentally. Galvanic exchange is used to replace the surface Pb atoms with Pt, and a surface distortion is found for Autextlessinftextgreater147textless/inftextgreater@Pttextlessinftextgreaterntextless/inftextgreater particles using molecular dynamics simulations in which the Pt-covered (100) facets shear into (111) diamond structures. DFT calculations of oxygen binding show that the distorted surfaces are the most active for the ORR, and that their activity is similar regardless of the Pt coverage. These calculations are consistent with rotating ring-disk voltammetry measurements. textcopyright 2012 The Royal Society of Chemistry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper we report the electrochemical synthesis of core@shell dendrimer-encapsulated nanoparticles (DENs) consisting of cores containing 147 Au atoms (Autextlessinftextgreater147textless/inftextgreater) and Pt shells having ∼54 or ∼102 atoms (Autextlessinftextgreater147textless/inftextgreater@Pttextlessinftextgreaterntextless/inftextgreater (n = 54 or 102)). The significance of this work arises from the correlation of the experimentally determined structural and electrocatalytic properties of these particles with density functional theory (DFT) calculations. Specifically, we describe an experimental and theoretical study of Pb underpotential deposition (UPD) on Autextlessinftextgreater147textless/inftextgreater DENs, the structure of both Autextlessinftextgreater147textless/inftextgreater@Pbtextlessinftextgreaterntextless/inftextgreater and Autextlessinftextgreater147textless/inftextgreater@Pt textlessinftextgreaterntextless/inftextgreater DENs, and the activity of these DENs for the oxygen reduction reaction (ORR). DFT calculations show that Pb binding is stronger on the (100) facets of Au as compared to (111), and the calculated deposition and stripping potentials are consistent with those measured experimentally. Galvanic exchange is used to replace the surface Pb atoms with Pt, and a surface distortion is found for Autextlessinftextgreater147textless/inftextgreater@Pttextlessinftextgreaterntextless/inftextgreater particles using molecular dynamics simulations in which the Pt-covered (100) facets shear into (111) diamond structures. DFT calculations of oxygen binding show that the distorted surfaces are the most active for the ORR, and that their activity is similar regardless of the Pt coverage. These calculations are consistent with rotating ring-disk voltammetry measurements. textcopyright 2012 The Royal Society of Chemistry.
4.
Wenjie Tang, Liang Zhang, Graeme Henkelman, "Catalytic Activity of Pd/Cu Random Alloy Nanoparticles for Oxygen Reduction", The Journal of Physical Chemistry Letters, 2, 11, 2011, 1328-1331.
@article{Tang2011,
title = {Catalytic Activity of Pd/Cu Random Alloy Nanoparticles for Oxygen Reduction},
author = {Wenjie Tang and Liang Zhang and Graeme Henkelman},
url = {https://zhanglab-thu.com/wp-content/uploads/2020/12/publications/jz2004717.pdf, PDF},
doi = {10.1021/jz2004717},
issn = {1948-7185},
year = {2011},
date = {2011-06-01},
journal = {The Journal of Physical Chemistry Letters},
volume = {2},
number = {11},
pages = {1328--1331},
abstract = {Trends in oxygen reduction activity of Pd/Cu bimetallic random alloy nanoparticles are determined with calculations of oxygen binding for a range of compositions. A reduction in the average oxygen binding is found as Cu is added to Pd, indicating an increase in catalytic activity up to a peak at 1:1 Pd/Cu ratio. Calculations show that Cu reduces the Pd-O binding energy and Pd increases the Cu-O binding energy. These changes are understood in terms of charge transfer from Pd to Cu, lowering the d-band center of Pd and raising that of Cu. The peak in activity occurs because these two effects not equivalent. A greater overlap between the d-states of Pd and the adsorbed oxygen makes the reduction in binding at Pd more significant than the increase in binding at Cu. We present a simple model of the average binding energy that can generally predict activity trends in random alloys. textcopyright 2011 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Trends in oxygen reduction activity of Pd/Cu bimetallic random alloy nanoparticles are determined with calculations of oxygen binding for a range of compositions. A reduction in the average oxygen binding is found as Cu is added to Pd, indicating an increase in catalytic activity up to a peak at 1:1 Pd/Cu ratio. Calculations show that Cu reduces the Pd-O binding energy and Pd increases the Cu-O binding energy. These changes are understood in terms of charge transfer from Pd to Cu, lowering the d-band center of Pd and raising that of Cu. The peak in activity occurs because these two effects not equivalent. A greater overlap between the d-states of Pd and the adsorbed oxygen makes the reduction in binding at Pd more significant than the increase in binding at Cu. We present a simple model of the average binding energy that can generally predict activity trends in random alloys. textcopyright 2011 American Chemical Society.
3.
Yan Zhang, Fuhua Li, Shuwei Li, Zedong Zhang, Zhiyi Sun, Yuhai Dou, Rui Su, Yahe Wu, Liang Zhang, Wenxing Chen, Dingsheng Wang, Yadong Li, "Asymmetric Dual-Atomic Catalyst with Axial Chloride Coordination for Efficient Oxygen Reduction Reaction", Advanced Materials, 2507478.
@article{https://doi.org/10.1002/adma.202507478b,
title = {Asymmetric Dual-Atomic Catalyst with Axial Chloride Coordination for Efficient Oxygen Reduction Reaction},
author = {Yan Zhang and Fuhua Li and Shuwei Li and Zedong Zhang and Zhiyi Sun and Yuhai Dou and Rui Su and Yahe Wu and Liang Zhang and Wenxing Chen and Dingsheng Wang and Yadong Li},
url = {https://advanced.onlinelibrary.wiley.com/doi/abs/10.1002/adma.202507478},
doi = {https://doi.org/10.1002/adma.202507478},
journal = {Advanced Materials},
volume = {n/a},
number = {n/a},
pages = {2507478},
abstract = {Abstract Low-platinum-group metal (low-PGM) catalysts play a crucial role in reducing the cost of proton exchange membrane fuel cells (PEMFCs). Dual-atomic catalysts offer valuable solutions due to their exceptional performance. This work explores the application of axial Cl-coordinated Pt─Co dual atoms on N-doped graphitic carbon (Pt1Co1/NC─Cl) catalysts utilizing PtCo dual-atomic catalysts, demonstrating their ability to significantly enhance the acidic oxygen reduction reaction (ORR) catalytic performance of conventional PtCo catalysts. The half-wave potential (E1/2) reaches 0.841 V in a 0.1 M HClO4 solution, and only a reduction of 12 mV in E1/2 is observed after 5000 cycles. Axial Cl proves to be resistant to removal during the electroreduction reaction. Consequently, the use of heteroatom-modulated asymmetric structures can greatly improve the performance of Pt-based catalysts. Incorporating nonmetallic synergistic Pt-group metals presents a promising solution for achieving high-performance Low-PGMs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract Low-platinum-group metal (low-PGM) catalysts play a crucial role in reducing the cost of proton exchange membrane fuel cells (PEMFCs). Dual-atomic catalysts offer valuable solutions due to their exceptional performance. This work explores the application of axial Cl-coordinated Pt─Co dual atoms on N-doped graphitic carbon (Pt1Co1/NC─Cl) catalysts utilizing PtCo dual-atomic catalysts, demonstrating their ability to significantly enhance the acidic oxygen reduction reaction (ORR) catalytic performance of conventional PtCo catalysts. The half-wave potential (E1/2) reaches 0.841 V in a 0.1 M HClO4 solution, and only a reduction of 12 mV in E1/2 is observed after 5000 cycles. Axial Cl proves to be resistant to removal during the electroreduction reaction. Consequently, the use of heteroatom-modulated asymmetric structures can greatly improve the performance of Pt-based catalysts. Incorporating nonmetallic synergistic Pt-group metals presents a promising solution for achieving high-performance Low-PGMs.
2.
Yan Zhang, Fuhua Li, Shuwei Li, Zedong Zhang, Zhiyi Sun, Yuhai Dou, Rui Su, Yahe Wu, Liang Zhang, Wenxing Chen, Dingsheng Wang, Yadong Li, "Asymmetric Dual-Atomic Catalyst with Axial Chloride Coordination for Efficient Oxygen Reduction Reaction", Advanced Materials, 2507478.
@article{https://doi.org/10.1002/adma.202507478c,
title = {Asymmetric Dual-Atomic Catalyst with Axial Chloride Coordination for Efficient Oxygen Reduction Reaction},
author = {Yan Zhang and Fuhua Li and Shuwei Li and Zedong Zhang and Zhiyi Sun and Yuhai Dou and Rui Su and Yahe Wu and Liang Zhang and Wenxing Chen and Dingsheng Wang and Yadong Li},
url = {https://advanced.onlinelibrary.wiley.com/doi/abs/10.1002/adma.202507478},
doi = {https://doi.org/10.1002/adma.202507478},
journal = {Advanced Materials},
volume = {n/a},
number = {n/a},
pages = {2507478},
abstract = {Abstract Low-platinum-group metal (low-PGM) catalysts play a crucial role in reducing the cost of proton exchange membrane fuel cells (PEMFCs). Dual-atomic catalysts offer valuable solutions due to their exceptional performance. This work explores the application of axial Cl-coordinated Pt─Co dual atoms on N-doped graphitic carbon (Pt1Co1/NC─Cl) catalysts utilizing PtCo dual-atomic catalysts, demonstrating their ability to significantly enhance the acidic oxygen reduction reaction (ORR) catalytic performance of conventional PtCo catalysts. The half-wave potential (E1/2) reaches 0.841 V in a 0.1 M HClO4 solution, and only a reduction of 12 mV in E1/2 is observed after 5000 cycles. Axial Cl proves to be resistant to removal during the electroreduction reaction. Consequently, the use of heteroatom-modulated asymmetric structures can greatly improve the performance of Pt-based catalysts. Incorporating nonmetallic synergistic Pt-group metals presents a promising solution for achieving high-performance Low-PGMs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract Low-platinum-group metal (low-PGM) catalysts play a crucial role in reducing the cost of proton exchange membrane fuel cells (PEMFCs). Dual-atomic catalysts offer valuable solutions due to their exceptional performance. This work explores the application of axial Cl-coordinated Pt─Co dual atoms on N-doped graphitic carbon (Pt1Co1/NC─Cl) catalysts utilizing PtCo dual-atomic catalysts, demonstrating their ability to significantly enhance the acidic oxygen reduction reaction (ORR) catalytic performance of conventional PtCo catalysts. The half-wave potential (E1/2) reaches 0.841 V in a 0.1 M HClO4 solution, and only a reduction of 12 mV in E1/2 is observed after 5000 cycles. Axial Cl proves to be resistant to removal during the electroreduction reaction. Consequently, the use of heteroatom-modulated asymmetric structures can greatly improve the performance of Pt-based catalysts. Incorporating nonmetallic synergistic Pt-group metals presents a promising solution for achieving high-performance Low-PGMs.
1.
Yan Zhang, Fuhua Li, Shuwei Li, Zedong Zhang, Zhiyi Sun, Yuhai Dou, Rui Su, Yahe Wu, Liang Zhang, Wenxing Chen, Dingsheng Wang, Yadong Li, "Asymmetric Dual-Atomic Catalyst with Axial Chloride Coordination for Efficient Oxygen Reduction Reaction", Advanced Materials, 2507478.
@article{https://doi.org/10.1002/adma.202507478d,
title = {Asymmetric Dual-Atomic Catalyst with Axial Chloride Coordination for Efficient Oxygen Reduction Reaction},
author = {Yan Zhang and Fuhua Li and Shuwei Li and Zedong Zhang and Zhiyi Sun and Yuhai Dou and Rui Su and Yahe Wu and Liang Zhang and Wenxing Chen and Dingsheng Wang and Yadong Li},
url = {https://advanced.onlinelibrary.wiley.com/doi/abs/10.1002/adma.202507478},
doi = {https://doi.org/10.1002/adma.202507478},
journal = {Advanced Materials},
volume = {n/a},
number = {n/a},
pages = {2507478},
abstract = {Abstract Low-platinum-group metal (low-PGM) catalysts play a crucial role in reducing the cost of proton exchange membrane fuel cells (PEMFCs). Dual-atomic catalysts offer valuable solutions due to their exceptional performance. This work explores the application of axial Cl-coordinated Pt─Co dual atoms on N-doped graphitic carbon (Pt1Co1/NC─Cl) catalysts utilizing PtCo dual-atomic catalysts, demonstrating their ability to significantly enhance the acidic oxygen reduction reaction (ORR) catalytic performance of conventional PtCo catalysts. The half-wave potential (E1/2) reaches 0.841 V in a 0.1 M HClO4 solution, and only a reduction of 12 mV in E1/2 is observed after 5000 cycles. Axial Cl proves to be resistant to removal during the electroreduction reaction. Consequently, the use of heteroatom-modulated asymmetric structures can greatly improve the performance of Pt-based catalysts. Incorporating nonmetallic synergistic Pt-group metals presents a promising solution for achieving high-performance Low-PGMs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract Low-platinum-group metal (low-PGM) catalysts play a crucial role in reducing the cost of proton exchange membrane fuel cells (PEMFCs). Dual-atomic catalysts offer valuable solutions due to their exceptional performance. This work explores the application of axial Cl-coordinated Pt─Co dual atoms on N-doped graphitic carbon (Pt1Co1/NC─Cl) catalysts utilizing PtCo dual-atomic catalysts, demonstrating their ability to significantly enhance the acidic oxygen reduction reaction (ORR) catalytic performance of conventional PtCo catalysts. The half-wave potential (E1/2) reaches 0.841 V in a 0.1 M HClO4 solution, and only a reduction of 12 mV in E1/2 is observed after 5000 cycles. Axial Cl proves to be resistant to removal during the electroreduction reaction. Consequently, the use of heteroatom-modulated asymmetric structures can greatly improve the performance of Pt-based catalysts. Incorporating nonmetallic synergistic Pt-group metals presents a promising solution for achieving high-performance Low-PGMs.