Catalytic decomposition of N_2O on Pd_xCu_y alloy catalysts: A density functional theory study

摘要

The density functional theory (DFT) calculations were performed to investigate the catalytic activities of Pd, Cu, and PdxCuy alloy catalysts for N2O reduction reaction (NRR). The activation and dissociation of N2O on PdxCuy catalysts were explored. The rate-determining step for the NRR was the dissociation of N2O into N-2 and O. The electronic structure of PdxCuy alloys was determined by both ligand and strain effects, but was not closely related to the catalytic activity for NRR because two kinds of surface Pd and Cu atoms are differently involved in active sites for molecular adsorption and dissociation. Owing to the different role of Pd and Cu in NRR, the PdCu catalyst had both strong N2O adsorption strength and easier N2O dissociation than did pure and Pd3Cu catalysts, and therefore had the highest catalytic activity for NRR among the PdxCuy alloy catalysts. These fundamental findings were further applied to predict the thermal and electrochemical NRR.