CunTM: Promising catalysts for preferential oxidation of CO in H2-rich gas.

Preferential oxidation of CO (PROX) is an important reaction for removing CO to a parts-per-million level from the hydrogen-rich stream. Recent experimental results show single-atom alloys (SAAs) of Cu surfaces doped by transition-metal (TM) of group VIII (TM = Ni, Pd, Pt) exhibit excellent catalytic performance toward hydrogenation and a variety of oxidation reactions including PROX of CO. To unravel mechanism, we performed DFT calculations to investigate. Cu n Pt exhibited higher activity for both H 2 dissociation and the PROX when compared with Cu n Ni and Cu n Pd. Especially, Cu 6 Pt emerges as the best surface for both H 2 dissociation and the PROX. The investigation on catalytic mechanism, we first found the element step is the formation of hydroxyl and atomic oxygen simultaneously. This work provides insight into the Cu-TM SAA catalysts, which may give helpful information for design of Cu-based catalysts for industrially important PROX. [ABSTRACT FROM AUTHOR]