Hydrophobic Surface Modification of Cu-Based Catalysts for Enhanced Semihydrogenation of Acetylene in Excess Ethylene

Cu-based catalysts have gained significant attention in the semihydrogenation of acetylene, a vital industrial process for ethylene stream purification. Nevertheless, their potential has been hindered by limited activity and stability issues stemming from polymerization. Here, we provide a surface enrichment strategy with hydrophobic modification that enriches the remaining trace amounts of acetylene in the gas flow, thereby avoiding the additional temperature rise required due to limited mass transfer under complete conversion conditions. The decrease in reaction temperature and steric hindrance of hydrophobic chains on the surface of Cu reduced the coupling side reaction, thereby improving the selectivity (84%) and stability (>120 h) at full conversion. Particularly, this was achieved by the synergistic catalysis among CuCx, Cu, and hydrophobic chains due to the in situ phase transition of Cu during the reaction. This strategy is expected to shed light on the reported nonprecious metal catalysts for further improvement of catalytic performance.