摘要
采用程序升温脱附方法表征用于碳八芳烃异构化的MOR、RIZ分子筛的酸性质,并用间二甲苯歧化/异构化反应表征分子筛的催化性能。NH_3-TPD脱附动力学分析得到RIZ和MOR分子筛强酸的脱附活化能分别为115.4kJ/mol和178.9kJ/mol。RIZ具有2种强酸位,强酸总量约为MOR的3倍。在370℃、常压下的MX转化反应表明,RIZ分子筛比MOR分子筛的催化活性更高,歧化反应随反应的进行而明显减少。RIZ分子筛的歧化初活性与强酸量有对应关系,与酸强度无关。
The acidity properties of MOR and RIZ zeolites for C_8 aromatics isomerization were investigated by the temperature program desorption method.The m-xylene disproportionation/isomerization reactions were used to analyze the catalytic performance of the two zeolites.The desorption activation energies of strong acid sites calculated by NH_3-TPD desorption kinetics model is 115.4 kJ/mol and 178.9 kJ/mol for MOR and RIZ,respectively.RIZ has two types of strong acid sites and 3 times the total amount of strong acid sites than MOR.The results of the m-xylene disproportionation/isomerization reactions at 370 ℃ and atmospheric pressure indicate the higher activity of RIZ than MOR.The disproportionation over RIZ significantly decreases with on-stream time.The initial activity of disproportionation over RIZ is proportional to strong acid amount but is independent of the acid strength.
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2017年第11期76-81,共6页
Petroleum Processing and Petrochemicals
基金
中国石油化工股份有限公司合同项目(416029)
关键词
分子筛
程序升温脱附
酸性
异构化
歧化
zeolites
temperature program desorption
acidity
isomerization
disproportionation
