LAUSR

Abstract To reveal the influence of shell Pd ensemble form in the core–shell Pd@M (M = Cu, Ag, Au) catalysts on the catalytic performance of C2H2 semi-hydrogenation, the mechanism of C2H2 semi-hydrogenation on Pd@M catalysts with different shell Pd ensemble are fully investigated using DFT and microkinetic modeling calculations. The results show that C2H4 selectivity and its formation activity closely depend on the shell Pd ensemble form; among Pd@Cu with different shell Pd ensemble, C2H4 selectivity and its formation activity has a volcano curve relationship with the d-band center of Pd@Cu, in which Pd7@Cu with the shell Pd ensemble of dimer and trimer is the best due to the moderate d-band center. The same things also occur on the Pd@Ag and Pd@Au. It is proposed that controlling the ensemble form of shell noble-metal Pd may be a good way to adjust the catalytic performance toward the selective hydrogenation of other alkynes.