CO Electro-oxidation using near-surface alloys of platinum and transition metals

Abstract

The purpose of this thesis is to analyze the trends of near-surface alloys (NSAs) of platinum and transition metals toward CO electro-oxidation to CO2, in order to identify promising electrode materials to perform the reaction. To do so, Density Functional Theory (DFT) simulations were performed. This work is composed of two parts: the first part consists of modeling the reaction on the (111) facet of NSAs of platinum and transition metals, while the final part considers the (331) facet. The first part is subdivided into 5 sections: the first section introduces the surface that is going to be modeled as well as the target catalytic reaction. The second one shows the catalytic trends as a function of the number of valence electrons of the guest transition metal. The third one compares a simple adsorption model to a co-adsorption model. The fourth one examines whether linear scalability of the intermediates exists and provides volcano-type activity plots to determine promising candidates. Lastly, the fifth section deals with the effect of the transition metal coverage on the most active alloy. The composition of the second part is similar, except for the co-adsorption model and the analysis of coverage effects, which were not performed. The results reveal that the most promising alloys are the (111) facet of Pt-Mn NSAs and the (331) facet of Pt-Os NSAs.