Selectivity-controllable hydrogen transfer reduction of α,β-unsaturated aldehydes over high-entropy catalysts

Selective catalytic reduction of α,β-unsaturated aldehydes plays a significant role in the present chemical industry. In this article, a series of high entropy catalysts were prepared and employed to catalyze the hydrogen transfer reaction of furan-2-acrolein in alcoholic solvents. As a result, the catalyst containing inexpensive Cu, Co, Al, Ni, and Fe elements exhibited outstanding performance, in which more than 99.9% conversion and 93.3% selectivity to 2-furan propanol are obtained in the presence of the CuCoAlNiFeOx catalyst; meanwhile, the furan ring-hydrogenated products 3-(tetrahydrofuran-2-yl)propanal and 3-(tetrahydrofuran-2-yl)propan-1-ol are mainly generated using CuCoAlNiFe-250R as the catalyst. Based on the results of control experiments and catalyst characterization, it is concluded that the synergistic effect between the five different metal elements is very crucial to the prominent catalytic activity. Moreover, the presence of metal Cu is advantageous for the hydrogenation of the side chain CC and CO bonds, while the reduced state Ni is responsible for the hydrogen transfer reduction of the furan ring. This study provides an economical and facile approach for the selective reduction of aromatic α,β-unsaturated aldehydes and biomass-derived furanic derivatives.