Preparation of Ni/SiO2 Catalysts by Sol-Gel Method Using Ionic Liquid as Solvent and Study on Their Performance for the Selective Hydrogenation of Citral

Ni/SiO2 catalysts with 10wt% Ni loading were prepared by modified sol-gel method using ionic liquid 1-methyl-3-butyl-imidazole tetrafluoroborate ([Bmim]BF4) as solvent at mild temperature. The as-prepared catalysts were applied in the selective hydrogenation of citral. The influences of the calcination temperature and the reduction temperature on their properties were investigated. The catalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermal analysis (TG-DSC). The results show that the optimum calcination temperature and reduction temperature are 873 K and 823 K, respectively.