Effect of graphene support on large Pt nanoparticles
Effect of graphene support on large Pt nanoparticles
State-of-the-art catalysts are often created via deposition of monolayers, sub-monolayers or nanoparticles of the catalytic material over supports, aiming to increase the surface area and decrease the loading of the catalytic material and therefore the overall cost. Here, we employ large-scale DFT calculations to simulate platinum clusters with up to 309 atoms interacting with single layer graphene supports with up to 880 carbon atoms. We compute the adsorption, cohesion and formation energies of two and three-dimensional Pt clusters interacting with the support, including dispersion interactions via a semi-empirical dispersion correction and a vdW functional. We find that three-dimensional Pt clusters are more stable than the two-dimensional when interacting with the support, and that the difference between their stabilities increases with the system size. Also, the dispersion interactions are more pronounced as we increase the nanoparticle size, being essential to a reliable description of larger systems. We observe inter-atomic expansion (contraction) on the closest (farthest) Pt facets from the graphene sheet and charge redistribution with overall charge being transferred from the platinum clusters to the support. The Pt–Pt expansion, which is related to the charge transfer in the system, correlates with the adsorption energy per Pt atom in contact with the graphene. These, and other electronic and structural observations show that the effect of the support cannot be neglected. Our study provides for the first time, to the best of our knowledge, quantitative results on the non-trivial combination of size and support effects for nanoparticles sizes which are relevant to catalyst design.
32713-32722
Verga, L.G.
aec51d68-4b36-4b34-8f70-ed4a624b3e08
Aarons, J.
93e68133-73b0-43e0-8c91-464920f4a503
Sarwar, M.
5b6c7791-3f9b-43a2-a0a3-38e8289a8fde
Thompsett, D.
6f7014d2-14b6-401e-9da9-7916d48a21dd
Russell, A.E.
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Skylaris, Chris
8f593d13-3ace-4558-ba08-04e48211af61
28 December 2016
Verga, L.G.
aec51d68-4b36-4b34-8f70-ed4a624b3e08
Aarons, J.
93e68133-73b0-43e0-8c91-464920f4a503
Sarwar, M.
5b6c7791-3f9b-43a2-a0a3-38e8289a8fde
Thompsett, D.
6f7014d2-14b6-401e-9da9-7916d48a21dd
Russell, A.E.
b6b7c748-efc1-4d5d-8a7a-8e4b69396169
Skylaris, Chris
8f593d13-3ace-4558-ba08-04e48211af61
Verga, L.G., Aarons, J., Sarwar, M., Thompsett, D., Russell, A.E. and Skylaris, Chris
(2016)
Effect of graphene support on large Pt nanoparticles.
Physical Chemistry Chemical Physics, 18 (48), .
(doi:10.1039/C6CP07334D).
Abstract
State-of-the-art catalysts are often created via deposition of monolayers, sub-monolayers or nanoparticles of the catalytic material over supports, aiming to increase the surface area and decrease the loading of the catalytic material and therefore the overall cost. Here, we employ large-scale DFT calculations to simulate platinum clusters with up to 309 atoms interacting with single layer graphene supports with up to 880 carbon atoms. We compute the adsorption, cohesion and formation energies of two and three-dimensional Pt clusters interacting with the support, including dispersion interactions via a semi-empirical dispersion correction and a vdW functional. We find that three-dimensional Pt clusters are more stable than the two-dimensional when interacting with the support, and that the difference between their stabilities increases with the system size. Also, the dispersion interactions are more pronounced as we increase the nanoparticle size, being essential to a reliable description of larger systems. We observe inter-atomic expansion (contraction) on the closest (farthest) Pt facets from the graphene sheet and charge redistribution with overall charge being transferred from the platinum clusters to the support. The Pt–Pt expansion, which is related to the charge transfer in the system, correlates with the adsorption energy per Pt atom in contact with the graphene. These, and other electronic and structural observations show that the effect of the support cannot be neglected. Our study provides for the first time, to the best of our knowledge, quantitative results on the non-trivial combination of size and support effects for nanoparticles sizes which are relevant to catalyst design.
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Accepted/In Press date: 18 November 2016
e-pub ahead of print date: 18 November 2016
Published date: 28 December 2016
Organisations:
Faculty of Natural and Environmental Sciences
Identifiers
Local EPrints ID: 404288
URI: http://eprints.soton.ac.uk/id/eprint/404288
ISSN: 1463-9076
PURE UUID: 08487b3f-2c2a-4047-bb03-3d2dd84a66c7
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Date deposited: 05 Jan 2017 12:04
Last modified: 16 Mar 2024 03:51
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Author:
L.G. Verga
Author:
J. Aarons
Author:
M. Sarwar
Author:
D. Thompsett
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