PbO-Yb_2O_3催化苯酚与碳酸二甲酯的酯交换反应

Transesterification of Dimethyl Carbonate and Phenol over PbO-Yb_2O_3 Catalyst

制备了一系列固体催化剂用于苯酚(PhOH)与碳酸二甲酯(DMC)酯交换合成碳酸二苯酯(DPC)。其中,铅镱复合氧化物催化剂活性较高,能多次回收使用。用正交实验方法详细研究了该催化剂焙烧温度、催化剂组成及反应温度等影响因素。实验结果表明:选择铅镱物质的量比为2:1,700℃下焙烧的催化剂,在n(PhOH):n(DMC)=2:1,反应温度170℃,反应16h时,得DMC转化率56.87%,DPC产率17.10%。碳酸甲苯酯(MPC)产率33.24%。该催化剂多次回收使用后仍有较好的活性。

A variety of solid catalysts used for the synthesis of diphenyl carbonate （DPC） by transesterification of dimethyl carbonate （DMC） with phenol were prepared, and the experiments show that among them, the catalyst of lead-ytterbium double oxide is the most suitable one for the transesterificational reaction because it has a higher catalytic activity, and it is also because of its good regeneration performance which causes it can be reused for several times without obvious activity loss. The effects of the molar ratio of Pb to Yb, the calcination temperature of the catalyst and the reaction temperature of the transesterificational on the yields of the products were investigated by the orthogonal experiments. The results show that under the conditions of Pb/Yb= 2：1, calcination temperature 700℃ and reaction temperature 170℃ for 16 h, the conversion of DMC is 56.87% and the yield of DPC and methyl phenyl carbonate （MPC） can reach 17.10% and 33.24%, respectively, and the catalytic activity of the PbO-Yb2O3 catalyst can still keep well after regeneration and being reused for several times.