甲醇气相羰化复合催化剂的制备及性能研究

Preparation and catalytic performance of composite catalyst for vapor phase carbonylation of methanol

用浸渍法制备了甲醇气相羰化Ni-Mo-La/AC三组分复合催化剂,用BET、XRD、XPS等表征手段进行了表征分析,并考察了催化剂制备因素对催化活性的影响。实验证明,在Ni-Mo/AC中加入稀土,可显著的提高Ni的表面分散,提高催化剂的催化活性,且选择性有利于醋酸。最佳催化剂的制备方法为用钼酸铵水溶液和硝酸镍、硝酸镧甲醇溶液两步浸渍活性炭。La最佳质量负载量为2.7%,催化剂焙烧和还原最合适的温度均为450℃。制得的催化剂,可获得96.72%的甲醇转化率和70.45%的羰化产物(醋酸甲酯和醋酸)产率。

Three-component catalyst Ni-Mo-La/AC was prepared by impregnation method and characterized by BET, XRD and XPS. The effects of preparation conditions on the catalytic activity were investigated. The results indicated that the addition of rareearth metals was favorable to Ni diffusion on the catalyst surface, and improved the catalytic activity and the selectivity to acetate acid. The optimum catalyst was prepared by two-step impregnating activated carbon with aqueous solution of ammonium molybdate and methanol solution of nickel nitrate and lanthanum nitrate. The optimum La loading was 2.7% by mass, and the optimum temperature for calcination and reduction of catalyst was 450℃. The prepared catalyst could obtain a molar yield of carbonyl compounds, methyl acetate and acetic acid, of 70.45% with a methanol conversion of 96.72%.