Particle Size and Shape Effects in Electrochemical Environments: Pd Particles Supported on Ordered Co3O4(111) and Highly Oriented Pyrolytic Graphite

Kastenmeier M, Fusek L, Deng X, Skala T, Mehl S, Tsud N, Grau S, Stumm C, Uvarov V, Johanek V, Libuda J, Lykhach Y, Myslivec J, Brummel O (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Journal of Physical Chemistry C American Chemical Society

Book Volume: 126

Pages Range: 12870-12881

Journal Issue: 30

DOI: 10.1021/acs.jpcc.2c03109

Abstract

Particle size and shape effects control the oxidation behavior of nanostructured electrocatalysts. We investigated the oxidation state of Pd nanoparticles supported on Ar⁺-sputtered highly oriented pyrolytic graphite (HOPG) and well-ordered Co3O4(111) films on Ir(100) as a function of electrode potential by means of synchrotron radiation photoelectron spectroscopy coupled with an ex situ emersion electrochemical (EC) cell. Scanning tunneling microscopy revealed the growth of hemispherical and flat Pd nanoparticles on Ar⁺-sputtered HOPG and Co3O4(111), respectively. The oxidation state of Pd nanoparticles is controlled by electronic metal support interaction (EMSI) associated with charge transfer at the interface. We found that the Pd nanoparticles are largely metallic on HOPG and partially oxidized on Co3O4(111). Specifically, we detected the formation of partially oxidized Pd^δ+aggregates in combination with atomically dispersed Pd²⁺species. The latter species dominate at small Pd coverage and form the metal/oxide interface at high Pd coverage. Immersion into an alkaline electrolyte (pH 10, phosphate buffer) at potentials between 0.5 and 1.1 VRHEhas no significant effect for Pd/Co3O4(111) but yields traces of surface Pd oxide at 0.9 and 1.1 VRHEfor Pd/HOPG. Formation of PdO was observed at 1.3 and 1.5 VRHE. Quantitative analysis suggests nearly one monolayer and nearly two monolayers of PdO on the surfaces of the Pd nanoparticles supported on HOPG and Co3O4(111) at 1.5 VRHE, respectively. The differences in the oxidation behavior reveal the decisive role of the EMSI in the stability of the metal/oxide interfaces in an EC environment.

Authors with CRIS profile

Maximilian Kastenmeier Lehrstuhl für Katalytische Grenzflächenforschung Lukáš Fusek Lehrstuhl für Katalytische Grenzflächenforschung Xin Deng Lehrstuhl für Katalytische Grenzflächenforschung Sebastian Grau Lehrstuhl für Katalytische Grenzflächenforschung Corinna Stumm Lehrstuhl für Katalytische Grenzflächenforschung Jörg Libuda Lehrstuhl für Katalytische Grenzflächenforschung Yaroslava Lykhach Collaborative Research Centre 1452/1 Catalysis at Liquid Interfaces (CLINT) Olaf Brummel Lehrstuhl für Katalytische Grenzflächenforschung

Additional Organisation(s)

Interdisziplinäres Zentrum Erlangen Catalysis Resource Center (ECRC)

Involved external institutions

Univerzita Karlova v Praze / Charles University in Prague

Czech Republic (CZ) Elettra Sincrotrone Trieste S.C.p.A.

Italy (IT)

How to cite

APA:

Kastenmeier, M., Fusek, L., Deng, X., Skala, T., Mehl, S., Tsud, N.,... Brummel, O. (2022). Particle Size and Shape Effects in Electrochemical Environments: Pd Particles Supported on Ordered Co3O4(111) and Highly Oriented Pyrolytic Graphite. Journal of Physical Chemistry C, 126(30), 12870-12881. https://doi.org/10.1021/acs.jpcc.2c03109

MLA:

Kastenmeier, Maximilian, et al. "Particle Size and Shape Effects in Electrochemical Environments: Pd Particles Supported on Ordered Co3O4(111) and Highly Oriented Pyrolytic Graphite." Journal of Physical Chemistry C 126.30 (2022): 12870-12881.

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