Cu-Loaded Catalysts for Efficient Hydrogenation of Furfural to Furfuryl Alcohol: Modulation of Hydrogenation Performance by Introducing Carbon Layer

Furfural, a key biomass-derived platform chemical, requires efficient hydrogenation for economic and research benefits. Herein, we propose a carbon-encapsulated catalyst with optimized active sites (using carbon-containing organics) for its highly selective hydrogenation. Experimental results demonstrated that carbon loading facilitated the conversion of strong acid sites to medium‑strong acid sites on the catalyst support, and also increased the Lewis/Brønsted (L/B) ratio. Through optimization of reaction conditions and carbon loading, complete conversion of furfural and a furfuryl alcohol selectivity as high as 99.17% were achieved at 160 °C for 4 h. The prepared catalyst maintained high furfuryl alcohol selectivity even after five cycles, owing to the protective carbon layer on the active support and the well-dispersed Cu species on its surface. DFT calculations further revealed that furfural preferentially adsorbs on the catalyst surface via the η¹(O)-aldehyde configuration, confirming the promotional role of the catalyst in furfural hydrogenation. Graphical