LAUSR

Abstract Aiming at understanding the effects of Pd coordination number and environment on the catalytic performance of C2H2 semi-hydrogenation, DFT calculations were performed to illustrate C2H2 semi-hydrogenation mechanism on the M(M = Cu, Ag, Au) alloyed single-atom Pd catalysts with surface Pd coordination numbers of 7, 8 and 9. The results indicate that PdCu with surface Pd coordination number of 8 not only shows best selectivity and its formation activity toward C2H4 formation, but also effectively inhibits green oil formation; the results are also obtained on the PdAg or PdAu with surface Pd coordination number of 8, which is attributed to the d-band center located moderately below the Fermi level. This study not only helps scientists understand C2H2 semi-hydrogenation mechanism on the metal alloyed single-atom Pd catalysts, but also provides valuable clues for the design of other partner metals alloyed single-atom Pd catalysts by controlling the coordination number and environment of single-atom Pd.