Electrocatalysis with Atomically Defined Model Systems: Metal-Support Interactions between Pt Nanoparticles and Co3O4(111) under Ultrahigh Vacuum and in Liquid Electrolytes

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F18%3A10389456" target="_blank" >RIV/00216208:11320/18:10389456 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1021/acs.jpcc.8b05594" target="_blank" >https://doi.org/10.1021/acs.jpcc.8b05594</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcc.8b05594" target="_blank" >10.1021/acs.jpcc.8b05594</a>

Result language

angličtina

Original language name

Electrocatalysis with Atomically Defined Model Systems: Metal-Support Interactions between Pt Nanoparticles and Co3O4(111) under Ultrahigh Vacuum and in Liquid Electrolytes

Original language description

Electronic metal-support interactions play a key role in the design of heterogeneous catalysts, as they provide a tool for tuning catalytic properties and enhancing catalyst stability. In this work, we explore the role of metal- support interactions in electrocatalysis using a model approach. We investigate the adsorption and reaction behavior of atomically defined Pt/Co3O4 model catalysts under ultrahigh vacuum (UHV) and under electrochemical conditions. The model systems were prepared by physical vapor deposition (PVD) of Pt onto well-ordered Co3O4(111) films on Ir(100), varying the average Pt nanoparticle (NP) size between 10 and 500 atoms per NP. In UHV, the model catalysts were characterized by synchrotron radiation photoelectron spectroscopy (SRPES), temperature-programmed desorption (TPD), and infrared reflection-absorption spectroscopy (IRAS). By SRPES, we show that partially oxidized Pt delta+ species are formed at the interface with the Co3O4 support. CO adsorbs weakly on these Pt delta+ sites and can be identified by IRAS at 115 K. Upon heating, CO adsorbed on metallic Pt-0 reacts with oxygen released from Co3O4 and gives rise to CO2 between 450 and 500 K. As a result of oxygen depletion, the Pt delta+ at the NP interface is reduced to Pt-0. Subsequently, we investigated the adsorption and oxidation of CO under electrochemical conditions on the same Pt/Co3O4 model catalysts. After preparation and characterization in UHV, the model systems were transferred into the electrochemical environment without exposure to ambient conditions. CO adsorption and electrooxidation were performed under conditions where the model system is stable (pH 10, 0.33-1.03 V-RHE, phosphate buffer). By electrochemical infrared reflection-absorption spectroscopy (EC-IRRAS), we show that CO does not adsorb at the partially oxidized Pt delta+ sites in the electrolyte at 300 K. Nevertheless, the Pet(delta+) species at the NP/oxide interface is reduced to Pt-0 upon repeated experimental cycles. This effect increases with decreasing NP size, in line with the behavior observed under UHV conditions. Our findings suggest that electronic metal-support interactions in metal/oxide catalysts play a very similar role in reactions with gaseous reactants and at the electrified interface.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Physical Chemistry C

ISSN

1932-7447

e-ISSN

—

Volume of the periodical

122

Issue of the periodical within the volume

36

Country of publishing house

US - UNITED STATES

Number of pages

13

Pages from-to

20787-20799

UT code for WoS article

000444920900025

EID of the result in the Scopus database

2-s2.0-85053293433