Structure-sensitive hydrogenation of NO using metal electrocatalysts

Abstract

The purpose of this thesis is to determine the most stable product of NO hydrogenation on a series of transition metal catalysts with sites of different surface coordination. Since it is unclear whether the first hydrogenated intermediate of NO electroreduction is *NOH or *NHO, this work will show the adsorption energies at 6 different active sites of 9 transition metals (Co, Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au). To do so, density functional theory (DFT) calculations were carried out using the VASP code and the adsorption energies were calculated by means of the computational hydrogen electrode. Once the adsorption energies are calculated, this work is divided into three parts: the first one shows the most favorable adsorption sites of *NO, *NOH and *NHO on each metal and surface site. The second part presents the findings from a thermodynamic perspective and with structural sensitivity of the most favorable product of *NO hydrogenation on transition metals. In the last part, universal adsorption-energy scaling relations are established among *NO, *NOH and *NHO.