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Catalytic activity of Pt_(38) in the oxygen reduction reaction from first-principles simulations

Sementa, Luca and Andreussi, Oliviero and Goddard, William A. and Fortunelli, Alessandro (2016) Catalytic activity of Pt_(38) in the oxygen reduction reaction from first-principles simulations. Catalysis Science and Technology, 2016 (18). pp. 6901-6909. ISSN 2044-4753. http://resolver.caltech.edu/CaltechAUTHORS:20160729-113609065

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Abstract

The activity of truncated octahedral Pt_(38) clusters as a catalyst in the oxygen reduction reaction (ORR) is investigated via first-principles simulations. Three catalytic steps: O_2 dissociation (O_(2ads) → 2_O_(ads)), O hydration (O_(ads) + H_2O_(ads) → 2OH_(ads)), and H_2O formation (OH_(ads) + H_(ads) → H_2O_(ads)) are considered, in which all reactant species are co-adsorbed on the Pt_(38) cluster according to a Langmuir–Hinshelwood mechanism. The minimum structures and saddle points for these different steps are then calculated at the density-functional theory (DFT) level using a gradient-corrected exchange–correlation (xc-)functional and taking into account the effect of the solvent via a self-consistent continuum solvation model. Moreover, first-principles molecular dynamics (AIMD) simulations in which the H_2O solvent is explicitly described are performed to explore dynamic phenomena such as fast hydrogen transfer via meta-stable hydronium-type configurations and their possible role in ORR reaction paths. By comparing the present findings with previous results on the Pt(111) surface, it is shown that in such a nanometer-size cluster the rate-determining-step (rds) corresponds to H_2O formation, at variance with the extended surface in which O hydration was rate-determining, and that the overall reaction barrier is actually increased with respect to the extended system. This is in agreement with and rationalizes experimental results showing a decrease of ORR catalytic activity in the nanometer-size cluster range.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1039/C6CY00750CDOIArticle
http://pubs.rsc.org/en/content/articlelanding/2016/cy/c6cy00750cPublisherArticle
ORCID:
AuthorORCID
Goddard, William A.0000-0003-0097-5716
Fortunelli, Alessandro0000-0001-5337-4450
Additional Information:© 2016 Royal Society of Chemistry. Received 4th April 2016, Accepted 26th June 2016. Latest Edition published: 30 Jun 2016. First published online 27 Jun 2016. We thank Scott Anderson and Stefan Vajda for stimulating discussions. Use of the Center for Nanoscale Materials was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Funders:
Funding AgencyGrant Number
Department of Energy (DOE)DE-AC02-06CH11357
Record Number:CaltechAUTHORS:20160729-113609065
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20160729-113609065
Official Citation:Catalytic activity of Pt38 in the oxygen reduction reaction from first-principles simulations Luca Sementa, Oliviero Andreussi, William A. Goddard III and Alessandro Fortunelli Catal. Sci. Technol., 2016, 6, 6901-6909 DOI: 10.1039/C6CY00750C
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:69309
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:29 Jul 2016 18:58
Last Modified:31 Mar 2017 01:46

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