Boosting primary amines renewable tandem synthesis via defect engineering of NiCo alloy

Reductive amination of biomass aldehydes is a vital process to synthesize chemical intermediates primary amine, but the selectivity is severely compromised by the self-condensation of highly reactive imine intermediates. Herein, we proposed a solution by manipulating the adsorption configuration of secondary imine via defect engineering. Specifically, a gradient reduction strategy was used to adjust the driving force of NiCo alloy crystallization, thus motivating the formation of metal vacancy clusters. The primary amine selectivity was raised from 70.9% to 95.1% with defect concentration increased from 36.1% to 42.5% on catalysts. In situ fourier transform infrared spectroscopy (FTIR) and density functional theory demonstrated metal vacancy clusters induced remarkable Ni-Co electron transfer, which strengthened electronic coupling between secondary imine with catalyst, resulting in a flat configuration that was conducive to CN bond breakage to guarantee smooth conversion into primary amines. This catalyst exhibited potential real-life application prospects for its low cost, universality in reductive amination of various aldehydes, and long-life reusability.