摘要
广泛用于合成农药、医药和染料等中间体的碳酸二甲酯,目前国内采用极毒的光气法生产,近几年来,国外采用了加压均相合成。至于常压下非均相合成则未见报导。我们从合成草酸二甲酯的文献[4]得到启发,采用甲醇常压羰化合成碳酸二甲醇,催化剂为Pd/C,并引进亚硝酸甲酯作为该催化合成反应的循环剂。反应如下所示:
The synthesis of dimethyl carbonate from carbon monoxide and methyl nitrite catalyzed by carbon-supported palladium in a flow system at atmospheric pressure has been studied. A kinetic measurement of the formation of dimethyl carbonate over various carbon-supported palladium catalysts was carried out in a fix bed microreactor. Reaction temperature ranging from 80 to 130℃ was chosen for the determination of activation energies which were varied between 40-96kJ/mol according to the different supports and promoters. The variation of catalytic activity and selectivity with reaction temperature over different catalysts were summerized. The promoter effect was demonstrated, by the addition of a certain amount of Li or Fe, the catalytic activity and selectivity for the formation of dimethyl carbonate were enhanced. Meanwhile the relationship between the catalytic activity and particle size of palladium determined by TEM was also studied.
