草酸二甲酯气相催化加氢合成乙二醇的研究

Study on hydrogenation of dimethyl oxalate to ethylene glycol

采用共沉淀法制备了一系列CuO/SiO2催化剂,进行草酸二甲酯气相加氢活性评价,分别考察了不同沉淀剂(Na2CO3、NH3.H2O、NaOH)、催化剂组成以及反应工艺条件对加氢性能的影响。采用N2吸附脱附、N2O吸附、XRD、TG热重分析、H2-TPR等手段对催化剂进行表征。结果表明,草酸二甲酯加氢反应活性与Cu0有关,提高铜比表面积有利于提高加氢活性。采用以NaOH沉淀剂制备的CuO质量分数为50%的CuO/SiO2催化剂,在200℃、2MPa、0.07h-1和氢酯摩尔比为100时,草酸二甲酯转化率可达98%,乙二醇选择性87%,且催化剂表现出较好的稳定性。

Vapor-phase hydrogenolysis of dimethyl oxalate to ethylene glycol was performed over a series of CuO/SiO2 catalysts with different precipitants（Na2CO3,NH3·H2O,NaOH） and CuO loading in a fixed-bed reactor at different reaction conditions.All catalysts were characterized by N2 physisorption,N2O-chemisorption,X-ray diffraction（XRD）,TG and H2 temperature-programmed reduction（H2-TPR） analysis technique.The results of catalytic tests and characterization indicate that the activity of catalysts is related with the Cu0 and improved with the increase of the Cu area.High conversion of dimethyl oxalate（98%） and selectivity to ethylene glycol（87%） were obtained over the optimal CuO/SiO2 catalyst（precipitated by NaOH and 50% CuO loading） at optimized reaction conditions.The CuO/SiO2 catalyst also exhibits good stability.