BNPd single-atom catalysts for selective hydrogenation of acetylene to ethylene: a density functional theory study

The mechanisms of selective hydrogenation of acetylene to ethylene on B11N12Pd single-atom catalyst (SAC) was investigated through the density functional theory by using 6-31++G basis set. We studied the adsorption characteristics of H2 and C2H2, and simulated the reaction mechanism. We have discovered that H2 absolutely dissociative chemisorption on single atom Pd and formed the B11N12Pd(2H) dihydride complex and then proceed the hydrogenation reaction with C2H2. The hydrogenation reaction of acetylene onto the B11N12Pd complies with the Horiuti-Polanyi mechanism, and the energy barrier as low as 26.55 kcal mol-1. The low desorption energy of ethylene, high ethylene hydrogenation activation energy can ensure the B11N12Pd SAC has high selectivity. Meanwhile it also has a higher selectivity than many bimetallic alloy single-atom catalyst.