Direct Conversion of Furfural to 1,5-Pentanediol over Zr-Doped CuCo-Based Catalyst

Taking into account that the selective ring-opening of the furan ring limits the efficiency of direct conversion of furfural to 1,5-pentanediol, a Zr-doped CuCo-based catalyst was developed to regulate the multistep reaction of furfural to 1,5-pentanediol in one pot and boost the overall step yield. Through the efficient synergistic action of multiple active sites, 56% yield of 1,5-pentanediol from furfural in one pot was obtained by Cu4.5Co3.5Zr1, surpassing other nonprecious metal catalysts. The improvement in the catalytic effect of this catalyst is attributed to doping CuCo-based species with Zr. The introduced Zr species not only provide medium-strength base sites but also promote the high dispersion of Cu atoms; both factors promote the conversion of furfural to furfuryl alcohol. Besides, Zr species promote the reduction of Cu/Co oxygen species, enriching oxygen vacancies, and combined with Co2+/Co3+ create an optimal Brønsted/Lewis acid ratio in Cu4.5Co3.5Zr1. Metals adjacent to oxygen vacancies adsorb oxygen species of compounds, and basic sites adsorb the H1-hydroxyl group of furfuryl alcohol. With the synergistic effect of Brønsted acid, the C2–O2 bonds of the furan ring are selectively polarized to enhance the selectivity toward 1,5-pentanediol. Additionally, dynamical reactions using furfural and furfuryl alcohol independently as feedstocks were conducted to investigate the reaction mechanism. The catalyst maintained stable performance over five runs with minimal deactivation. This work provides a method for improving the yield of 1,5-pentanediol from furfural over multiple nonprecious metal catalysts by enriching oxygen vacancies and combining suitable acid–base properties.