Single-atom alloy Pd1Ag10/Al2O3 catalyst: Effect of CO-induced Pd surface segregation on the structure and catalytic performance in the hydrogenation of C2H2

Abstract

The effective surface concentration of Pd1 sites composed of individual palladium atoms isolated from each other by Ag atoms in the Pd1Ag10/Al2O3 single-atom alloy (SAA) catalyst can be significantly enhanced by the adsorption-induced surface segregation upon a special pretreatment of the catalyst in a CO-containing atmosphere at 200 °C. The catalyst activity towards acetylene hydrogenation gets tripled without sacrificing selectivity for ethylene. The segregated surface of the catalyst is thus preserved under target reaction conditions.