Synthesis of Dual-Active-Sites Ni-Ni2In catalysts for selective hydrogenation of furfural to furfuryl alcohol

The rational design of efficient heterogeneous catalysts for selective hydrogenation of unsaturated aldehyde to unsaturated alcohol is a long-term scientific challenge and pursuit. Herein, we prepared an effective NiIn0.2/MgO-Al2O3 catalyst with dual active sites for hydrogenation of furfural (FAL) to furfuryl alcohol (FOL), delivering a high activity and a maximum 98.9% FOL yield. Moreover, the NiIn0.2/MgO-Al2O3 exhibited excellent catalytic performances for the other unsaturated aldehydes and good durability in a 100 h stability test. Characterization and theoretical calculations reveal that H2 and FAL are adsorbed and activated on the active sites of metallic Ni and Ni2In intermetallic compound, respectively. Hydrogenation of FAL to FOL occurs on the surface of Ni2In via hydrogen spillover from metallic Ni. Sequentially, FOL easily desorbs from the surface of Ni2In owing to the active-site isolation and electron transfer effect in Ni2In. The metal-IMCs dual-active-sites mechanism provides a novel strategy for synthesizing efficient hydrogenation catalysts.