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

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;催化剂; 甲基丙烯酸甲酯; 甲基丙烯醛; 氧化-酯化反应

Preparation and Application of Catalyst for Oxidative-esterification of Methacrolein to Methyl Methacrylate

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%.