甲基丙烯醛氧化酯化制甲基丙烯酸甲酯催化剂的制备与应用

Preparation and Application of Catalyst for Oxidativeesterification of Methacrolein to Methyl Methacrylate

将甲基丙烯醛制甲基丙烯酸甲酯(MMA)的氧化酯化2步反应简化为1步反应。用浸渍法制备了用于该反应的催化剂。实验表明,选择金属Pd为主要活性成分,添加Pb、Bi、Fe中的1种或几种,可提高催化剂的活性;组成为Pd5Bi2PbFe的催化剂负载在CaCO3上MMA的收率为62.4%,载体为SiO2或ZnO的催化效果次之,载体为MgCO3或ZrO2的催化效果较差。在CaCO3载体上,金属负载顺序依次为Pd、Pb、Bi、Fe的Pd5Bi2PbFe催化剂MMA的收率可达86.9%。在Pd5Bi2PbFe催化剂上添加稀土元素(除Sm和Dy)可提高生成MMA的选择性。使用Pd5Bi2PbFePr/CaCO3催化剂,MMA的产率可高达90.4%。

The two-step reaction for the preparation of methyl methacrylate(MMA) from methacrolein(MAL) via oxidative esterification was simplified to one-stage reaction. The catalysts were prepared by means of (impregnation) and applied to the oxidative esterification reaction of MAL. The results show that the catalytic (activity) of catalyst mainly containing Pd is increased by adding one, two or a combination of Pb,Bi and Fe. The yield of MMA can reach to 62.4% in the presence of catalyst Pd_(5)Bi_(2)PbFe carried on CaCO_(3); the catalyst carried on SiO_(2 ) or ZnO has a good activity; while the catalyst carried on MgCO_(3) or ZrO_(2) has no activity. When catalyst (Pd_(5)Bi_(2)PbFe) carried on CaCO_(3) with loading metal order:Pd, Pb, Bi, Fe was used in the reaction, the yield of MMA was 86.9%. The selectivity to methacrolein was improved observably when rare earth elements were added to catalysts Pd_(5)Bi_(2)PbFe. When catalyst Pd_(5)Bi_(2)PbFePr/CaCO_(3) was used to oxidative-esterification (reaction) of methacrolein, the yield of MMA could reach to 90.4%.