文献类型：期刊文献

中文题名：金属离子改性HZSM-5对尿素热解制氰胺反应的影响

英文题名：Effects of modified HZSM-5 with different metal ions and concentrations on urea pyrolysis to produce cyanamide and dicyandiamide

作者：卜芮[1];张浩[1];沈卫华[1];方云进[1]

机构：[1]华东理工大学化学工程联合国家重点实验室,上海200237

年份：2023

卷号：52

期号：4

起止页码：969

中文期刊名：应用化工

外文期刊名：Applied Chemical Industry

收录：CSTPCD;;北大核心:【北大核心2020】；CSCD:【CSCD_E2023_2024】；

基金：国家自然科学基金(21576083)。

语种：中文

中文关键词：尿素;单氰胺;双氰胺;离子交换;ZSM-5

外文关键词：urea;cyanamide;dicyandiamide;ion exchange;ZSM-5

摘要：采用不同金属离子对HZSM-5进行离子交换改性,探究不同金属离子和不同浓度锰离子交换改性对尿素转化率、单氰胺和双氰胺选择性的影响。通过XRD、NH_(3)-TPD、ICP-OES等测试对催化剂进行了表征,考察了不同离子和不同离子浓度交换对催化剂结构和酸类型、酸强度、酸中心数量的影响,并对催化剂性质与反应活性和选择性的关系进行了探究。结果表明,弱酸和中强酸为反应活性中心,B/L值高有利于尿素热解制单氰胺和双氰胺。不同浓度Mn离子改性,最佳浓度为0.2 mol/L。CeMn双金属改性ZSM-5具有良好催化效果,单双氰胺总选择性优于单一金属离子交换。
HZSM-5 Treated with different metal salt by ion exchange method,and the effect of different metal ions and different concentration of Mn^(2+)on the selectivity of cyanamide and dicyandiamide was investigated.The catalysts were characterized by XRD,NH_(3)-TPD,ICP-OES and other tests.The influence of ion exchange on the catalyst structure,type and intensity of acid sites was investigated.The results show that more weak acid sites and medium strong acid sites are the reaction active sites,and high B/L value is favorable for the pyrolysis of urea to produce cyanamide and dicyandiamide.Mn ion modification with different concentration,the best concentration is 0.2 mol/L.CeMn bimetal modified ZSM-5 has good catalytic effect,and the selectivity of cyanamide and dicyandiamide is better than that of single metal ion exchange.