Alloying palladium with copper on zirconium dioxide for accelerating the selective catalytic transfer hydrogenation of furfural to furfuryl alcohol†

Abstract

Utilizing metal alloying strategies to fully exploit the role of precious metals in upgrading biomass chemicals remains both a challenging task and a key sustainable strategy. To improve the hydrogen transfer efficiency of furfural molecules in the catalytic transfer hydrogenation pathway, we report a Pd–Cu alloy composite nanocatalyst supported on mesoporous-structured zirconia through electrospinning technology. The chemical states of Pd and Cu in the catalyst were studied using XRD, HRTEM and XPS characterization methods, proving the presence of the PdCu alloy. A series of synthesized monometallic and bimetallic catalysts were tested for their ability to catalyze the catalytic transfer hydrogenation of furfural. Results showed that the PdCu alloy catalyst exhibited excellent performance similar to that of the monometallic Pd catalyst. 95.6% furfural conversion and 91.5% furfuryl alcohol selectivity were achieved at 170 °C and 2 MPa N₂ for 12 h, and the catalytic activity did not decrease significantly after 6 cycles. The excellent catalytic activity was mainly attributed to the alloy and solvent effects, which promoted the improvement in hydrogen transfer efficiency.