Bimetallic copper- and nickel-rich Cu–Ni phyllosilicate catalysts for the liquid phase selective hydrogenation of furfural to furfuryl alcohol†

Abstract

Bimetallic Cu–Ni phyllosilicates (Cu–NiPS) with various Ni/Cu ratios (5 : 15, 10 : 10, 15 : 5 wt%) were synthesized using ammonia evaporation hydrothermal method to obtain copper-rich or nickel-rich Cu–Ni alloys. These catalysts were evaluated for the selective hydrogenation of furfural (FF) to furfuryl alcohol (FA) in the liquid phase under relatively mild conditions (100 °C, 20 bar H₂). The bimetallic Cu–NiPS catalysts exhibited excellent dispersion of the Ni–Cu alloy with average particle sizes ranging from 3.8 to 4.8 nm and demonstrated significantly enhanced catalytic performance over the monometallic nickel phyllosilicate (20% NiPS). The copper-rich Ni–Cu alloy (15% Cu–5% NiPS) exhibited the highest FF conversion efficiency (88%) and FA selectivity (90%). This superior performance is attributed to its smallest particle size, higher proportion of Cu⁰ and the synergistic interactions between Ni and Cu. This synergy effectively stabilizes the carbonyl group while promoting efficient H₂ dissociation and FA desorption, thereby facilitating the hydrogenation of FF to FA. Furthermore, the catalyst exhibited excellent recyclability and maintained high conversion efficiency and selectivity over multiple cycles.