碱处理对ZSM-11分子筛二甲苯异构化催化性能的影响  

EFFECT OF ALKALI TREATMENT ON CATALYTIC PERFORMANCEOF ZSM-11 FOR XYLENE ISOMERIZATION

作　　者：岳欣 刘中勋 康承琳 盖月庭 史军军 Yue Xin;Liu Zhongxun;Kang Chenglin;Gai Yueting;Shi Junjun(SINOPEC Research Institute of Petroluem Processing,Ltd.,Co.,Beijing 100083)

机构地区：[1]中石化石油化工科学研究院有限公司,北京100083

出　　处：《石油炼制与化工》2025年第4期77-85,共9页Petroleum Processing and Petrochemicals

基　　金：中国石油化工股份有限公司合同项目(224236)。

摘　　要：通过动态晶化法合成ZSM-11分子筛,并对其进行不同强度的碱处理改性。通过X射线衍射光谱、N 2吸附-脱附、X射线荧光光谱、核磁共振波谱、扫描电子显微镜、NH 3程序升温脱附和吡啶吸附红外光谱等表征手段对碱处理前后分子筛的物化性质进行对比分析,结果表明:碱处理可以脱除部分分子筛骨架Si,使分子筛形貌和结晶度发生变化,同时引入了一定量的介孔,形成贯通性更好的多级孔结构,使其比表面积增大;碱处理也能调变分子筛酸量,暴露出更多的酸中心,有利于提高催化剂的异构化活性。采用间二甲苯异构化作为探针反应,对分子筛催化性能进行评价,结果表明:使用浓度0.5 mol L的NaOH溶液处理后ZSM-11分子筛的二甲苯异构化活性提高效果最佳。ZSM-11 zeolite was synthesized by dynamic crystallization method and treated with different intensity of alkali to obtain the modified samples.The physical and chemical properties of the samples before and after alkali treatment were characterized and compared by using XRD,N 2 adsorption-desorption,XRF,NMR,SEM,NH 3-TPD and Py-FTIR.The results showed that part of the skeleton silicon atom of the ZSM-11 zeolite could be removed by alkali modification,changing the crystal morphology and crystallinity of samples,and a certain amount of mesoporous was introduced,forming a more interconnected hierarchical pore structure,which increased the specific surface area.Alkali treatment also could modulate the acid amount of ZSM-11 with more exposed acid sites which significantly enhance isomerization activity.The catalytic performances of the samples were evaluated by using m-xylene isomerization.The results showed that ZSM-11 treated with 0.5 mol L NaOH solution exhibited the best enhancement in m-xylene isomerization activity.

关 键 词：ZSM-11分子筛 碱处理 多级孔 间二甲苯 异构化 对二甲苯 邻二甲苯 

分 类 号：O64[理学—物理化学]