Restructuring of the gold-carbide interface for low-temperature water-gas shift†
Abstract
A passivated Au/α-MoC catalyst, containing 2–4 layered Au clusters of 1.6 nm, was re-activated by CH4/H2 at 590 °C, during which the structure of the gold-carbide interface changed considerably. The partially-oxidized surface Mo species were carburized to MoC, while the Au clusters dispersed into smaller ones, accompanied by the coating of carbide thin layers on Au. This restructuring promoted charge transfer from Au to MoC and extended the Au-MoC interfacial perimeter, which was largely responsible for the activity in the low-temperature water-gas shift reaction.