Selective Hydrogenation of Furfural over the Co-Based Catalyst: A Subtle Synergy with Ni and Zn Dopants

A multimetal doping strategy has aroused extensive attention in promoting a non-noble catalyst for selective hydrogenation reaction. Herein, a multimetallic catalyst (NiCoZn@CN) with excellent catalytic performance for hydrogenation of furfural (FAL) to furfuryl alcohol (FOL) is prepared through a facile, inexpensive, and efficient pyrolysis method. Using H2 as a H donor, extremely high selectivity (>99%) with 100% conversion is attained over the optimal NiCoZn@CN-600 catalyst. The subtle synergy between Co and Ni, Zn dopants, which remarkably promotes the performance of the Co-based catalyst, is revealed. In the NiCoZn@CN system, Co0 is proven to be the main active site, whose content is greatly improved by Ni and Co dopants. Additionally, the Ni dopant could also benefit activation of H2 and the Zn dopant could enhance metal nanoparticle dispersion and the porous structure of the catalyst. In situ FTIR indicates that the vertical adsorption mode of FAL with the Oaldehyde terminal on NiCoZn@CN-600 ensures a selective hydrogenation process. With a N-doped carbon matrix, NiCoZn@CN-600 shows good cycling stability in five times run. NiCoZn@CN-600 is also competent in the catalytic transfer hydrogenation (CTH) of FOL, affording >99% yield with 2-propanol as a H donor. This study opens an avenue toward rational design of multimetallic doping catalysts with high selectivity for challenging reactions in the conversion of biomass-derived compounds.