ترجمه مقاله نقش ضروری ارتباطات 6G با چشم انداز صنعت 4.0
- مبلغ: ۸۶,۰۰۰ تومان
ترجمه مقاله پایداری توسعه شهری، تعدیل ساختار صنعتی و کارایی کاربری زمین
- مبلغ: ۹۱,۰۰۰ تومان
Abstract
In carbonylation of ethylene glycol to ethylene carbonate with urea catalyzed by ZnO, which was considered as a heterogeneous catalyst. ZnO is observed to be dissolved in the reactants probably due to the formation of Zn(NCO)2(NH3)2 making the reaction homogeneously catalyzed. To our knowledge, it is firstly reported that the reaction experienced three states including ZnO dissolution, homogeneous catalysis, and precipitate formation. The precipitate was characterized to be a mixture containing Zn(OH)2, ZnCO3, and Zn(NCO)2with a ratio of 8.5:6.1:1. Possible mechanisms of ZnO dissolution and precipitation were proposed.
4. Conclusion
In the reaction of carbonylation of EG to EC with urea, ZnO is a precursor for the formation of homogenous catalyst Zn(NCO)2(NH3)2 rather than a heterogeneous catalyst. The reaction experienced three periods, the dissolution of ZnO, the homogeneous catalysis, and precipitate formation. To the best of our knowledge, it is the first time on the report of Zn(NCO)2(NH3)2 homogeneously catalyzed this reaction when ZnO is used. The precipitate after reaction has been analyzed to be a mixture of Zn(OH)2, ZnCO3, Zn(NCO)2 with ratio of 8.5:6.1:1.