甲基丙烯醛一步氧化酯化制备甲基丙烯酸甲酯

制备了用于甲基丙烯醛(MAL)一步氧化酯化为甲基丙烯酸甲酯(MMA)的新型催化剂. 在常压和连续搅拌的条件下，考察了反应条件对MAL转化率和MMA选择性的影响，并对反应动力学进行了初步研究. 实验结果表明：当反应温度50℃、氧气流速6 mL/min、甲醇与甲基丙烯醛的摩尔比75、催化剂在反应物中含量2.4%、反应时间60 min时，MAL的转化率可达99.4%, MMA的选择性为95.7%.

Preparation of Methyl Methacrylate by One-step Oxidative Esterification of Methacrolein

The two-step reaction for preparation of methyl methacrylate (MMA) from methacrolein (MAL) was simplified to a one-step oxidation-esterification reaction, a new catalyst was prepared and applied to this reaction in pending patents. Under the conditions of continuous stirring and atmospheric pressure the effects of reaction conditions on MAL conversion and MMA selectivity were systematically investigated. The results indicated that the catalyst Pd5Bi2Pb1Fe1/CaCO3 was active and could be used to the reaction of methacrolein one-step oxidation-esterification. The most appropriate reaction conditions are temperature 50℃, O2 velocity 6 mL/min, nMeOH/nMAL=75, catalyst 2.4% and reaction time 60 min. At the above conditions the MAL conversion and MMA selectivity reached up to 99.4% and 95.7% respectively. The apparent reaction kinetics for MAL was 1.1 order. The activation energy was 19.3 kJ/mol. The results confirm the feasibility of the new green technology for production of MMA.