Selective hydrogenation of furfural to furfuryl alcohol over copper-cobalt bimetallic catalyst

Cu-based catalysts have been widely studied as selectively hydrogenated furfural. However, due to the weak hydrogenation activity of the mono-metal copper-based catalyst, the interaction with furfural is usually weak, and the accessibility of the active site is severely limited. A micro-doping strategy was proposed in this study to solve these problems. Trace amounts of cobalt metal are doped into copper using equal volume impregnation. Compared with the Cu/MgO catalyst, the bimetallic CuCo/MgO-0.04 catalyst changes metal particles' size and valence and regulates the catalyst surface's electronic environment. Electron transfer occurs between Co and Cu, and many active sites are generated for adsorption and activation of CO double bonds, and hydrogenation reactions occur with adjacent H protons to improve the selectivity of furfuryl alcohol. CuCo/MgO-0.04 catalyst has excellent catalytic performance of 100 % furfural conversion and 99.4 % furfural alcohol selectivity. Combined with experimental data, kinetic studies, and theoretical calculations, it was confirmed that the d-band center shifted up in the catalyst doped with trace metal cobalt, which optimized the adsorption energy and configuration of furfural and reduced the reaction barrier more effectively. This study provides a strategy to support the partial doping of highly dispersed Cu nanoparticles with a small amount of Co metal. It achieves excellent catalytic properties and chemical selectivity in selective hydrogenation reactions.