【摘要】 甲硫醇是合成蛋氨酸等材料的重要有机化工原料,通过溶胶凝胶法结合浸渍法制备了K₂WO₄/Al₂O₃催化剂用于甲醇与硫化氢合成甲硫醇的反应。发现不同成胶pH值对于催化剂的孔道结构以及表面酸碱性质影响很大,从而影响催化剂的性能。当成胶pH值为6时,催化剂的比表面积最大,平均孔径和孔容最小;催化剂表面酸碱量适宜;催化剂活性最佳,在320—360℃反应温度下,甲硫醇的得率分别为77.4%,84.9%和87.1%。甲醇在催化剂表面甲氧基化受酸强度影响,酸度越高,产生的甲氧基数量越多,甲醇转化率增大。而表面碱数量的增加则使得硫化氢在催化剂表面解离成SH^-的数量越多,对甲硫醇的选择性越好。更多还原

【Abstract】 Methanthiol is an important chemical intermediate used to produce organosulfur compounds such as methionine. K₂WO₄/Al₂O₃ catalyst was prepared for the synthesis of methanethiol from methanol and hydrogen sulfide via sol-gel and impregnation method, and the effect of gelation pH values on the pore structure and surface acid-base properties of the catalyst were studied. When the gelation pH value was 6, the catalyst exhibited the maximum specific surface area, the minimum average pore diameter and pore volume, suitable surface acidity and basicity, and showed the best catalytic performance, the methanethiol yield of the catalyst was 77.4%, 84.9% and 87.1% respectively at the reaction temperature of 320-360 ℃. The methoxylation of methanol is strongly affected by the acid strength. The higher acidity promoted to generate more methoxides, and then gained higher methanol conversion. While the surface basicity made hydrogen sulfide dissociate into SH^-, and then enhanced the methanethiol selectivity.更多还原