Synergistic nanoalloy PdCu/TiO2 catalyst for in situ hydrogenation of biomass-derived furfural at room temperature

Abstract

This study reports a highly selective and efficiently recyclable PdCu/TiO₂ nanocatalyst for the in situ hydrogenation of biomass-derived furfural to furfuryl alcohol at room temperature using the readily available triethylsilane and methanol as the hydrogen donor. The finite dispersion of PdCu nanoalloys on the surface of shape-controlled TiO₂ nanorods facilitated synergistic acid-redox and more surface-exposed active metal sites, as elucidated by in situ pyridine FT-IR, H₂-TPR, and CO pulse chemisorption studies, respectively. Controlled reactions revealed that Pd is the key to in situ hydrogen generation from the mixture of triethylsilane and methanol. The PdCu/TiO₂ nanocatalyst (2 wt% Pd and 3 wt% Cu) exhibited a 97% yield of furfuryl alcohol at room temperature. In contrast, only 27 and 7% yields of furfuryl alcohol were obtained over Pd/TiO₂ and Cu/TiO₂ catalysts, respectively, confirming the synergistic role of the PdCu nanoalloy in the catalytic transfer hydrogenation (CTH) of furfural. The PdCu/TiO₂ nanocatalyst showed versatile efficiency in the CTH of various furfurals to achieve optimum yields of furfuryl alcohols at room temperature. The efficient gram-scale synthesis of furfuryl alcohol, the high stability of the PdCu/TiO₂ nanocatalyst as confirmed by the hot-filtration study, and the excellent catalyst reusability with 97 and 94% yields of furfuryl alcohol in the 1^st and 5^th cycles, respectively, emphasize the practical application of the developed catalytic process for the CTH of biomass-derived platform molecules at room temperature.