Structure Evolution of Ni-Cu Bimetallic Catalysts Derived from Layered Double Hydroxides for Selective Hydrogenation of Furfural to Tetrahydrofurfuryl Alcohol

The hydrogenation of furfural containing multifunctional group often needs the high-efficiency cooperation of multiple catalytic active centers, which is greatly determined by the regulation of the surface and interface structure of multicomponent catalytic materials. Based on such circumstance, a series of highly dispersed supported bimetallic Cu-Ni catalysts prepared by the in situ topological transformation of layered double hydroxides have been investigated for the one-pot hydrogenation of furfural. Compared with the supported monometallic Cu and Ni catalysts, the optimized bimetallic Cu1Ni3/MgAlO catalyst presents highly efficient and good selectivity in the hydrogenation of furfural at the bath reactor. The selectivity to tetrahydrofurfuryl alcohol reaches 94.0% with a complete conversion of furfural at 110 degrees C under 3 MPa of H-2 for 3 h. The results of TEM and in situ FT-IR confirm that the Ni-rich Cu-Ni alloy in the Cu1Ni3/MgAlO catalyst generates a strong synergistic effect, which shifts the adsorption configuration of furfural from parallel or vertical adsorption to tilted adsorption so as to significantly improve the catalytic performance. The intrinsic catalytic performances of CuxNiy/MgAlO catalysts indicate that the TOFC=O and TOFC=C values can be balanced through construction of the structure of the catalyst for achieving the synergistic effect between Cu and Ni significantly to enhance the one-pot selective hydrogenation of furfural to tetrahydrofurfuryl alcohol. Additionally, the Cu1Ni3/MgAlO catalyst presents excellent reusability by six-cycle testing. The above results indicate that the Cu1Ni3/MgAlO with the cooperation of multiple catalytic active centers is a promising catalyst for the selective hydrogenation of furfural.