WU Dingping, XU Ling, XIAO Qiang, ZHONG Yijun, ZHU Weidong
(Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004)
Abstract: 3-Methylcrotonaldehyde (3-MeCal) is one of typical α,β-unsaturated aldehydes. The hydrogenated product 3-methylcrotonalcohol (3-MeCol) of the C=O has a wide application in the production of perfumes, pharmaceuticals, and pesticides etc., as an important organic intermediate. In this contribution, Co/Al2O3 catalysts were prepared by a deposition-precipitation method and were used in the liquid-phase selective hydrogenation of 3-MeCal to 3-MeCol. The effect of the reaction temperature, the H2 initial pressure, and the calcination and reduction temperature of the catalysts were investigated. The results indicated that the catalyst displayed a good performance at the reaction temperature of 80 ℃ and a H2 initial pressure of 1ⅹ106 Pa. The H2-TPR technique was employed to investigate the effect of calcination temperature on the catalysts, indicating that an increase in calcination temperature could enhance the interactions between cobalt species and alumina support. The optimized catalyst prepared with calcination at 600 ℃ and followed by reduction at 550 ℃ exhibited an excellent performance. After 48 minutes, the conversion of 3-MeCal could reach 23.0 % with the selectivity for 3-MeCol of 88.6 %. Additionally, the prepared Co/Al2O3 catalysts exhibited excellent magnetic properties. Under a magnetic field, the catalyst powder could be easily separated from the liquid-phase reaction system. The catalysts did not show any significant degradation in the hydrogenation of 3-MeCal after three-cycle reuse, indicating the good recyclability of the prepared Co/Al2O3 catalysts.
Key words: Co/Al2O3; 3-methylcrotonaldehyde; selective hydrogenation; magnetic catalyst
E-mail: xiaoq@zjnu.cn
Journal of Molecular Catalysis, Vol. 26, Issue 4, 2012,308-313
