溶剂对完全液相法制CuZnAl浆状催化剂结构和性能的影响

采用完全液相法,以拟薄水铝石为铝源,选择不同溶剂溶解催化剂前体硝酸铜和硝酸锌制备了CuZnAl浆状催化剂,并采用X射线粉末衍射、氮吸附.X射线光电子能谱和程序升温还原对其进行了表征,考察了CuZnAI浆状催化剂在合成气一步法合成二甲醚反应中的催化性能.结果表明,不同的溶剂对催化剂性能有显著的影响,其中以乙二醇为溶剂制备的催化荆相结构稳定,孔径及孔体积最大,表面铜含量高,可还原铜量较多且还原温度偏低,从而在保证DME选择性不变的条件下显著提高了催化剂CO转化率.

Effect of solvent on the structure and performance of CuZnAl catalyst prepared by complete liquid phase technology

Al-based slurry catalysts using pseudo-boehmite as aluminum source were prepared by complete liquid phase technology, and the catalyst precursors Cu(NO_3)_2 and Zn(NO_3)_2were dissolved in different solvents. The as-prepared catalysts were characterized by means of X-ray diffraction, N_2 adsorption, Xray photoelectron spectroscopy and H_2 temperature-programmed reduction. Performance of the catalysts was evaluated in a slurry reactor for the synthesis of dimethyl ether (DME) from syngas. Results indicated that different solvent has significant influence on the catalyst structure and performance. Using glycol as solvent, the catalyst shows a stable phase structure and largest pore diameter and pore volume, meanwhile, the catalyst has more reducible copper and can be easily reduced. Therefore, the catalyst shows enhanced CO conversation while keeping the DME selectivity unchanged.