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

Journal article


Publication Details

Author(s): Faisal F, Bertram M, Stumm C, Wähler T, Schuster R, Lykhach Y, Neitzel A, Skala T, Tsud N, Beranova K, Prince KC, Matolin V, Brummel O, Libuda J
Journal: Journal of Physical Chemistry C
Publisher: AMER CHEMICAL SOC
Publication year: 2018
Volume: 122
Journal issue: 36
Pages range: 20787-20799
ISSN: 1932-7447
eISSN: 1932-7455


Abstract

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.


FAU Authors / FAU Editors

Bertram, Manon
Lehrstuhl für Physikalische Chemie II
Lehrstuhl für Physikalische Chemie II
Brummel, Olaf Dr.
Lehrstuhl für Physikalische Chemie II
Faisal, Firas
Lehrstuhl für Physikalische Chemie II
Libuda, Jörg Prof. Dr.
Stumm, Corinna
Professur für Physikalische Chemie
Lehrstuhl für Physikalische Chemie II
Lykhach, Yaroslava
Lehrstuhl für Physikalische Chemie II
Neitzel, Armin
Schuster, Ralf
Professur für Physikalische Chemie
Wähler, Tobias
Lehrstuhl für Physikalische Chemie II


Additional Organisation
Exzellenz-Cluster Engineering of Advanced Materials


External institutions with authors

Elettra Sincrotrone Trieste S.C.p.A.
Univerzita Karlova v Praze / Charles University in Prague


Research Fields

D Catalytic Materials
Exzellenz-Cluster Engineering of Advanced Materials


How to cite

APA:
Faisal, F., Bertram, M., Stumm, C., Wähler, T., Schuster, R., Lykhach, Y.,... Libuda, J. (2018). Electrocatalysis with Atomically Defined Model Systems: Metal-Support Interactions between Pt Nanoparticles and Co3O4(111) under Ultrahigh Vacuum and in Liquid Electrolytes. Journal of Physical Chemistry C, 122(36), 20787-20799. https://dx.doi.org/10.1021/acs.jpcc.8b05594

MLA:
Faisal, Firas, et al. "Electrocatalysis with Atomically Defined Model Systems: Metal-Support Interactions between Pt Nanoparticles and Co3O4(111) under Ultrahigh Vacuum and in Liquid Electrolytes." Journal of Physical Chemistry C 122.36 (2018): 20787-20799.

BibTeX: 

Last updated on 2019-06-08 at 09:05