水热陈化对Cu/SiO_2催化剂催化草酸二甲酯加氢制乙二醇的影响

Effect of hydrothermal treatment on performance of Cu/SiO_2 catalysts for hydrogenation of dimethyl oxalate to ethylene glycol

以水热处理方法,对均匀沉积沉淀法(尿素为沉淀剂)制备的Cu/SiO_2催化剂进行陈化处理,考察了催化剂陈化处理过程中水热温度以及时长对草酸二甲酯加氢制备乙二醇反应性能的影响。研究结果表明:水热陈化温度为120℃,水热时长为36h时催化剂表现出较好的催化性能。在固定床反应器中,当反应温度为473K,反应压力为2MPa,n(H_2)/n(DMO)为80,液时空速为1.0h^-1,草酸二甲酯的转化率达到100%,乙二醇的选择性达到96.2%。BET、SEM表征结果表明:水热陈化处理的温度和时长会影响催化剂孔结构微观形貌、活性组分的还原性能,从而影响了Cu/SiO_2催化剂的性能。

The Cu/SiO_2 catalyst prepared by coprecipitation method with urea as precipitator were treated by hydrothermal aging. Effects of hydrothermal treatment temperature and time on the performance of the catalysts for hydrogenation of dimethyl oxalate（DMO） to ethylene glycol（EG） were investigated. The results showed that the catalyst treated at 120℃ for 36 h exhibited optimal catalytic activity and selectivity, obtaining a DMO conversion of 100% and a EG selectivity of 96.2% under the reaction conditions of 473 K, 2MPa, H_2/DMO mole ratio of 80 and LHSV of 1.0 h^-1. BET and SEM characterization results indicated that both of hydrothermal temperature and time affected the structure and reducibility of the Cu/Si O_2 catalysts, thereby affecting their catalytic performances.