Catalytic furfural hydrogenation to furfuryl alcohol over Cu/SiO2 catalysts: A comparative study of the preparation methods

Abstract

Furfuryl alcohol, a vital intermediate for the production of foundry resins, fragrances, pharmaceuticals and pesticide, is produced by hydrogenation of furfural in gas phase or liquid phase. The furfuryl alcohol production in gas phase over silica supported copper catalyst is favored thanks to the environmental and technical advantages. The effect of preparation methods of silica supported copper catalysts on the structure and performance was investigated by means of ICP, N2 physisorption, ex-situ/in-situ XRD, in-situ XPS, FT-IR, H2-TPR, TEM, N2O titration, TG as well as furfural hydrogenation. The results indicated that the different catalyst synthesis strategies led to the diverse copper species in the calcined samples and disparate Cu0 surface area as well as different molar ratio of Cu+/(Cu+ + Cu0) in the fresh samples. The performance of impregnation derived sample was poorer than that of commercial CuCr-Strem catalyst. The catalysts prepared by deposition precipitation and ion exchange exhibited similar performance to the CuCr-Strem. The ammonia evaporation derived catalyst (Cu/SiO2-EA) showed superior performance in the activity, selectivity and stability among all the studied catalysts. The excellent performance was related to the highest surface area of Cu0, smallest copper particle size, large surface area and pore volume as well as appropriate higher Cu+/(Cu+ + Cu0) ratio. Furthermore, all the copper catalysts went through deactivation, which was caused by carbon deposition, during the reaction. Owing to the largest amount of Cu0 sites and large SBET, the Cu/SiO2-EA exhibited the slowest deactivation rate.