| Ethylene glycol (EG) is an important organic raw material. However, at present,EG is mainly synthesized by ethylene oxide hydrolysis, which is highly dependent onthe price of crude oil and constrained by the accompanying huge energy consumption.Therefore, it is urgent for us to development a new synthetic route which is scientificand reasonable utilization of resources to produce EG. The coupling reaction of CO toproducing oxalates and through further hydrogenation reaction to prepare EG isconsidered very promising route. However, the bottleneck of this route is developinghigh performance hydrogenation catalyst, thereby, it is significant to study andoptimize the synthesis of hydrogenation catalyst for oxalates.In this paper, Cu-based catalyst for the hydrogenation of diethyl oxalate (DEO) toEG was studied. Ethanol was added during the preparation of the catalyst and thecontent of ethanol as solvent and washing agent were investigated. The catalysts hadhigher activity when ethanol concentration was10%~20%(vol.) in solvent. Inaddition, methyl alcohol, ethanol and isopropanol as washing agent on theperformance of catalyst were compared. The results indicated that different washingagents had different effects on the double pore structure of the catalyst. The catalystwashed buy40%ethanol solution had highest activity and stability, with theconversion of DEO approached100%and the selectivity of EG was almost90%.Meanwhile, the catalyst washed by methyl alcohol presented high selectivity ofMPEG, which is a simple and convenient method to modulate catalyst.Moreover, the effects of transition metal La, Ce, Zr, Mo as the promoters of Cucatalysts was studied. It is found that La could improve the stability of the catalyst athigh temperatures by preventing it from sintering. A amount of Zr or Mo are in favorof Cu distribution and enhance the effect on catalyst activity. Ce as a promoter,produces adverse effects on Cu dispersion, and results in agglomeration of copperparticles. |
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