Dual Active Sites of Ni and FeNi<sub>3</sub> Constructed from Layered Double Hydroxides for One-Pot Hydrogenation of Furfural to Tetrahydrofurfuryl Alcohol
Rongrong Li, Wenqi Liu, Huibin Liu, Hongyu Niu, Quan Zhou, Changhai Liang, Xiao Chen
Abstract
One-pot hydrogenation of biomass-derived furfural with multiple reduction sites requires suitable metal sites to achieve a high value-added chemical in high yield. In this work, nonprecious Ni–Fe bimetallic catalysts with high efficiency derived from Fe x Ni y /MgAl-LDH hydrotalcite precursors are prepared for one-pot sequential hydrogenation of furfural to tetrahydrofurfuryl alcohol at mild conditions. Through fine adjustment of metallic Fe/Ni molar ratios in hydrotalcite precursors, bimetallic Fe x Ni y /MgAlO catalysts can be constructed. The topological transformation of hydrotalcite precursors provides a mesoporous structure for bimetallic supported catalysts. Due to the formation of the Ni–Fe alloy, there is an electron transfer from Fe to Ni in the catalyst due to the higher electronegativity of Ni than that of Fe, which greatly influences the adsorption of furfural on the surface of catalysts. Comparing the structures and catalytic performances of monometallic Ni/MgAlO and Fe/MgAlO catalysts, the Ni-rich Fe 1 Ni 4 /MgAlO catalyst with the dual active sites of metallic Ni and FeNi 3 alloy presents high efficiency in sequential hydrogenation of the C═O bonds and C═C bonds of furfural to tetrahydrofurfuryl alcohol with the yield of 90.3% under 3 MPa H 2 and 80 °C for 3 h, which can be an alternative for noble metal catalysts. Additionally, the Ni-rich Fe 1 Ni 4 /MgAlO catalyst presents excellent cycling stability. This design strategy for nonprecious NiFe bimetallic catalysts not only provide promising candidates for effective utilization of biobased furfural but also extend the application of bimetallic catalysts derived from hydrotalcite precursors for one-pot hydrogenation reactions.