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  • 1 Shanghai University Green Chemical Engineering and Energy (GCEE) Research Center 201800 Shanghai People’s Republic of China
  • | 2 Chinese Academy of Sciences Shanghai Institute of Applied Physics 201800 Shanghai People’s Republic of China
  • | 3 Chinese Academy of Sciences State Key Laboratory of Coal Conversion, Institute of Coal Chemistry 030001 Taiyuan People’s Republic of China
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Abstract  

The reaction of urea with ZnO was investigated by FTIR and TPD. It was found that urea was thermally decomposed into isocyanic acid on ZnO, and the adsorbed isocyanic acid reacted with ZnO to form zinc isocyanate. Catalytic evaluation showed that ZnO had high activity towards urea methanolysis in a batch reactor, and zinc element and isocyanate were all detected in the product solution. Furthermore, the soluble zinc content was proportional to the DMC yield. Sample analyses suggested that the soluble zinc existed in the form of Zn(NCO)2(NH3)2, which originated from the reaction of ZnO with urea. It was the complex (not ZnO) that catalyzed the urea methanolysis. Based on these observations, a possible mechanism was suggested.