Abstract: Through using ethylamine (EA),ethylenediamine (EDA),and triethylamine (TEA) respectively to adjust the pH of solution,and three kinds of cerium dioxide (CeO2) carriers with different surface oxygen vacancy concentrations are prepared by co-precipitation method.In addition,the performance of the catalyst in ammonia synthesis is further improved by optimizing the synthetic conditions of the carriers and adding different additives into the catalyst.It is found that Ru-based catalyst has the best performance as it is supported by CeO2-EDA-500-11-j prepared under the conditions that the pH of the solution is adjusted to around 11 by EDA,cerium source is added drop by drop,and the precursor is calcined at 500℃.The catalytic activity of 4% CS-2.5% Ru/CeO2-EDA-500-11-j in ammonia synthesis reaches 25.5 mmol/(g·h) under the conditions of 450℃,3 MPa,and n(H2)/n(N2)=3 (60 mL·min-1).XPS and H2-TPR test results show that CeO2 in 2.5% Ru/CeO2-EDA-500-11-j catalyst has higher concentration of Ce3+,more oxygen vacancies and appropriate base density,which are important factors for obtaining higher activity in ammonia synthesis.
王伟刚, 王鹏, 王爽. 有机胺调控CeO2载体及其催化合成氨性能的研究[J]. 现代化工, 2022, 42(10): 200-208.
WANG Wei-gang, WANG Peng, WANG Shuang. Regulation of CeO2 carrier by organic amines and study on its catalytic performance in ammonia synthesis. Modern Chemical Industry, 2022, 42(10): 200-208.
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