Promotional effect of Pd single atoms on Au nanoparticles supported on silica for the selective hydrogenation of acetylene in excess ethylene

A Pd single-atom alloy (SAA) structure was constructed by alloying Pd with Au supported on silica. The XRD and HRTEM results demonstrated that the addition of a small amount of Pd efficiently prevented the sintering of Au nanoparticles. The DRIFTS and EXAFS results confirmed that the Pd SAA structure was formed when the atomic ratios of Pd/Au were lower than 0.025. The Pd SAA structure exhibits a much better catalytic performance for the selective hydrogenation of acetylene in excess ethylene than the corresponding monometallic Au or Pd systems.