Hydrogenation of Furfural to Furfuryl Alcohol over PdCu/zirconium Phosphonate with Metal and Lewis Acid Sites

Abstract

Hydrogenation of furfural to furfuryl alcohol under H2 and N2 atmosphere was studied over zirconium phosphonate (ZrPO)‐supported PdCu (PdCu/ZrPO) catalysts. The direct hydrogenation and transfer hydrogenation activities of PdCu metal active sites and the transfer hydrogenation activity of Zr4+−O2− Lewis acid‐basic sites were investigated, respectively. The size and the distribution of Cu particles could be adjusted by altering the P/Zr molar ratio. Bimetallic PdCu could enhance the acidity of the PdCu/ZrPO catalysts, and improve the ratio of Lewis/Brønsted acid, which led to an increase in the transfer hydrogenation activity of Lewis acid‐basic pairs. The electronic effect between Pd and Cu promoted furfural to absorb onto electron‐deficient Cu through η1(O)‐aldehyde configuration, which contributed to the direct hydrogenation and the transfer hydrogenation at metal active sites. Especially, the adsorption and dissociation of H2 in electron‐rich Pd were promoted, which significantly improved the direct hydrogenation activity.