摘要
以大孔SiO2为载体,醋酸铯为主活性组分,添加氧化锆助剂采用浸渍法制备了Cs-ZrO2/SiO2催化剂,用于以丙酸甲酯(MP)、甲醛为主要原料的甲基丙烯酸甲酯(MMA)合成反应。考察了助剂ZrO2添加及其含量、原料中水含量、反应温度、原料酯醛摩尔比、进料空速等因素对MMA合成反应的影响,并利用ICP、BET表征手段对催化剂失活原因进行了研究。结果表明,水对反应的影响很大,水含量增大会导致产物收率降低;无水条件下,催化剂中ZrO2含量0.5%,丙酸甲酯/甲醛(摩尔比)3∶1,反应温度340℃,空速300 h-1时反应活性最好,MMA选择性可达94%;ICP、BET表征分析表明,催化剂失活的主要原因是催化剂结构被破坏所致。
Cs-ZrO2/ SiO2 catalyst was prepared by impregnation method with macroporous SiO2 as the carrier,cesium carbonate as the main active component,and ZrO2 as the additives. The catalyst was used for the synthesis of methyl methacrylate（ MMA）. In this reaction,methyl propionate（ MP）,and formaldehyde was the main raw materials. The effects of adding ZrO2 and its content,water content,reaction temperature,molar ratio of ester and aldehyde,and space velocity on the synthesis of MMA were investigated,the ICP,BET characterization methods were used to study the deactivation reason. The results showed that the influence of water on the reaction was great,water content increased would lead to reduce the product yield; it also showed that the reaction activity was best,and the selectivity of MMA reached 94%,under the conditions as follows： anhydrous,the content of ZrO2 in the catalyst was 0. 5%,methyl propionate /formaldehyde（ molar ratio） was 3∶ 1,reaction temperature was 340 ℃,space velocity was 300 h- 1; ICP,BET characterization analysis showed that the catalyst deactivation was mainly caused by destruction of the catalyst structure.
出处
《应用化工》
CAS
CSCD
北大核心
2015年第6期1083-1087,共5页
Applied Chemical Industry
