Atomically dispersed Au catalysts for preferential oxidation of CO in H2-rich stream

Carbon monoxide preferential oxidation (CO-PROX) is regarded as a promising strategy to remove trace amount of CO in H2-rich stream. Herein, atomically dispersed Au catalysts with different Au contents supported on cerium-zirconium solid solution supports were obtained by a deposition-precipitation method. The optimal catalyst, with 0.02 wt% Au, exhibits nearly 100 % CO conversion and 50 % CO2 selectivity for CO-PROX reaction under PEMFC working temperature range (80-120 degrees C) and remains catalytically stable after 72 h testing at 80 degrees C. The superior catalytic performances are attributed to the strong adsorption of CO and the low energy barrier of CO oxidation reaction, as well as the weak H2 adsorption and dissociation over highly dispersed Au single atoms, as supported by density functional theory calculations. Furthermore, combining characterization and experimental results, it is concluded that although catalysts are atomically dispersed, their performances can be adjusted by the synergetic interaction between neighboring Au single atoms.