Berlin 2018 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 53: Solid-liquid interfaces: Reactions and electrochemisty III (joint session O/CPP)
CPP 53.1: Vortrag
Mittwoch, 14. März 2018, 15:00–15:15, MA 144
Atomically-Defined Pt/Co3O4(111) as Model Electrocatalyst — •Manon Bertram, Corinna Stumm, Firas Faisal, Yaroslava Lykhach, Olaf Brummel, and Jörg Libuda — Physikalische Chemie II, FAU Erlangen
The surface science approach, i.e. studying model catalysts in ultra-high vacuum (UHV), is well known in heterogeneous catalysis. We apply this approach to electrocatalysis and transfer complex, but well-defined catalysts from UHV to electrochemical (EC) conditions.
As a model system we prepared Pt nanoparticles (NPs) on ordered Co3O4(111) thin films on Ir(100). The oxide support and the complete catalyst were characterized by low-energy electron diffraction (LEED), x-ray photoelectron spectroscopy (XPS) and other methods. We transferred the systems to EC environments under ultra-clean conditions. With a scanning flow cell coupled to an inductively coupled plasma mass spectrometer and EC infrared reflection-absorption spectroscopy (EC-IRRAS), LEED, and XPS we determined the stability window for the oxide support under EC conditions.
Using Pt/Co3O4(111) with different Pt loadings, we followed the CO electro-oxidation by EC-IRRAS and cyclic voltammetry. As reference, we studied CO adsorption under UHV conditions with infrared reflection absorption spectroscopy. We identify different adsorption sites, a suppression of bridging CO on small NPs, and electronic metal support interactions (EMSI) leading to formation of partially oxidized Pt. The EMSI influences the CO adsorption and, thus, the electrocatalytic properties.