Selective transformation of biomass-derived 5-hydroxymethylfurfural to the building blocks 2,5-bis(hydroxymethyl)furan on α-Ni(OH)₂/SiO₂ catalyst without prereduction

A series of low-cost α-Ni(OH)₂/SiO₂ catalysts were successfully fabricated by the vapor-induced internal hydrolysis method, then the hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-bis(hydroxymethyl)furan (BHMF) was investigated by using the ethanol as the hydrogen donor over these as-prepared α-Ni(OH)₂/SiO₂ catalysts. Based on the reaction results, these as-prepared catalysts, which could dispense with extra pre-reduction treatment before reactions, exhibited superior catalytic performance for the HMF hydrogenation to BHMF. A remarkable intrinsic selectivity of BHMF selectivity of almost 100% with about 90% HMF conversion could be obtained under 195 °C for 5 h in an N₂ atmosphere over the α-Ni(OH)₂/SiO₂ catalyst of 5-Ni(OH)₂/SiO₂ with about 5 wt% Ni on SiO₂. The almost constant HMF conversion and BHMF intrinsic selectivity found from the recycling tests can indicate that the catalyst was stable without the obvious loss of its catalytic activity after recycling. Moreover, the mechanism of HMF hydrogenation using ethanol over the α-Ni(OH)₂/SiO₂ catalysts could be referred to as the mechanism of the Meerwein-Ponndorf-Verley reaction. This work will provide a simple synthesis method for future design and development of high-performance, low-cost, and low-energy consumption catalysts for HMF hydrogenation to BHMF.