Study on the vapor phase hydrogenation of furfural to 2-methylfuran on Cu/ZnO catalyst

A series of Cu/ZnO catalysts were prepared by using co-precipitation method and their performance for the furfural gas phase hydrogenation to 2-methylfuran was investigated in a fixed bed reactor. The catalysts were characterized by X-ray diffraction (XRD), N₂ adsorption desorption, H₂ temperature programmed reduction (H₂-TPR), scanning electron microscope (SEM) and NH₃-temperature programmed desorption (NH₃-TPD) techniques to analyze the roles of Cu⁰ and ZnO. The results showed that Cu⁰ was the active center for the furfural hydrogenation and the addition of ZnO in Cu catalysts can reduce the crystal size, enhance the surface area, improve the reduction and increase the surface acidity of the catalysts. When the molar ratio of Cu/Zn molar ratio is 1:2, Cu₁Zn₂ catalyst showed the highest selectivity to 2-methylfuran due to its suitable numbers of redox active centers and weak acidic sites. Under the atmospheric pressure, reaction temperature of 200℃, 4:1 molar ratio of hydrogen to furfural and furfural volume space velocity of 0.3 h^-1, the conversion of furfural reached almost 100.0% with 93.6% selectivity to 2-methylfuran over Cu₁Zn₂ catalyst.