Cu-based nanocatalysts have potential applications in the selective hydrogenation of biomass-derived platform molecules. Currently, a main challenge is the poor stability of Cu catalysts under harsh reaction conditions due to metallic Cu sintering and agglomeration. Herein, a series of Cu x Fe y /Al 2 O 3 nanocomposite catalysts was prepared via controlled solution combustion synthesis (SCS) owing to its minimal reaction time and energy requirements that reduce Cu agglomeration. Among them, the Cu 5 Fe 3 /Al 2 O 3 catalyst exhibited the most favorable structure with the smallest grain size of 2.09 nm, highest dispersion of 63.6%, and an optimal Cu + /Cu 0 ratio of 1.0 than the traditional Cu/Al 2 O 3 counterpart. The synergy between Fe 2 O 3 and Cu inhibited the thorough reduction of Cu 2+ to Cu 0 and consequently facilitated H 2 dissociation and activation as well as the highly efficient activation of the ethyl levulinate’s (EL) carbonyl group. Unlike the traditional Cu/Al 2 O 3 catalyst, for which activity rapidly decreased from 97% to 11% over 200 h, the Cu 5 Fe 3 /Al 2 O 3 catalyst exhibited a high GVL yield of 85% and maintained excellent stability, attributable to the strong interaction between Cu nanoparticles and Al 2 O 3 support as well as the confinement effect with barrier property of Fe doping. Therefore, the inexpensive, efficient, and stable Cu 5 Fe 3 /Al 2 O 3 catalyst has potential applications in the selective hydrogenation of biomass-derived platform compounds. Solution combustion synthesis was employed to prepare a Cu–Fe/Al 2 O 3 nanocomposite catalyst, which exhibited excellent catalytic performance in the hydrogenation of biomass-derived ethyl levulinate to γ-valerolactone (GVL). This catalyst surpassed the performance of the traditional Cu/Al 2 O 3 catalyst, particularly in terms of demonstrating a high GVL yield of 85% and maintaining stability for over 200 h. This excellent performance could be attributed to its high Cu dispersion, small grain size, and optimal Cu + /Cu 0 ratio.
Fang et al. (Tue,) studied this question.