A green solvent diverts the hydrogenation of γ–valerolactone to 1,4 - pentandiol over Cu/SiO2

Solvent Effects in the Preparation of Catalysts Using Activated Carbon as a Carrier

The role of solvents is crucial in catalyst preparation. With regard to catalysts prepared with activated carbon (AC) as the carrier, when water is used as a solvent it is difficult for the solution to infiltrate the AC. Because AC comprises a large number of C atoms and is a nonpolar material, it is more effective for the adsorption of nonpolar substances. Since the water and active ingredients are polar, they cannot easily infiltrate AC. In this study, the dispersion of the active component was significantly improved by optimizing the solvent, and the particle size of the active component was reduced from 33.08 nm to 15.30 nm. The specific surface area of the catalyst is significantly increased, by 10%, reaching 991.49 m²/g. Under the same reaction conditions, the conversion of acetic acid by the catalyst prepared with the mixed solvent was maintained at approximately 65%, which was 22% higher than that obtained using the catalyst prepared with water as the solvent.

Vapour-Phase Selective Hydrogenation of γ-Valerolactone to 2-Methyltetrahydrofuran Biofuel over Silica-Supported Copper Catalysts

2-Methyltetrahydrofuran (MTHF) is a desirable biomass-based platform chemical with excellent potential as an ideal biofuel, green solvent, and raw material for synthesizing downstream chemicals. In this work, a series of copper nanoparticles encapsulated on SiO₂ were prepared by the wet impregnation method and evaluated as efficient non-noble metal catalysts for the vapour-phase hydrogenation of γ-valerolactone (GVL) to MTHF in a fixed-bed reactor under mild reaction conditions. The obtained catalyst properties were determined by XRD, FE-SEM, TEM, UV-DRS, TPR, NH₃-TPD, N₂O decomposition and pore size distribution measurements. Meanwhile, the parameters/variables tuning their catalytic performance (activity, conversion, selectivity and stability) were examined. Various Cu loadings featured on the SiO₂ support are essential for tuning the catalytic activity. Among the catalysts tested, a 5 wt% Cu/SiO₂ catalyst showed a 97.2% MTHF selectivity with 71.9% GVL conversion, and showed a stability for 33 h time-on-stream, achieved at 260 °C and atmospheric pressure conditions. It was found that a huge dispersion of Cu metal in support, hydrogen activation ability, abundant acidic sites and surface area are all beneficial for improved MTHF selectivity.