Sterically controllable adsorption on nickel surface for selective reductive amination

Surface and interfacial engineering of supported metal catalysts is crucial for enhancing catalytic selectivity. In this study, we employed Ni nanoparticles as a model to demonstrate the effectiveness of modification with silica and ammonia in developing stable, active, and selective Ni catalysts for reductive aminations. Our results showed that the modified Ni catalyst exhibited high selectivity toward thermodynamically unfavorable but highly desired compounds in the reductive amination of molecules with multiple reducible groups, whereas the general Ni catalyst underwent deep hydrogenation. Mechanism studies revealed that silica and ammonia modifications can sterically adjust the adsorption configurations of molecules from flat lying to linear, thereby altering product selectivity. Notably, this simple strategy can be applied to develop highly active and selective practical catalysts from commercial Raney Ni catalysts for reductive aminations.