酸掺杂原位合成多级孔SAPO34及用于催化甲醇制烯烃反应  

Acid-doped in-situ synthesis of hierarchical SAPO-34 and applied in the catalytic methanol to olefin reaction

作　　者：邵川 王银忠 秦冬玲 杨刚 SHAO Chuan;WANG Yinzhong;QIN Dongling;YANG Gang(State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211800, China)

机构地区：[1]南京工业大学化工学院材料化学工程国家重点实验室,江苏南京211800

出　　处：《南京工业大学学报（自然科学版）》2021年第5期600-608,共9页Journal of Nanjing Tech University(Natural Science Edition)

摘　　要：采用原位合成法,向分子筛合成母液中加入酸,成功制备出表面呈类沙漏形状的多级孔SAPO34分子筛。通过X线衍射仪(XRD)、扫描电子显微镜(SEM)、物理吸附仪(BET)、X线荧光光谱(XRF)、化学吸附仪(NH3TPD)、同步热分析仪(TG)等仪器对分子筛进行表征,并将其应用于甲醇制烯烃(MTO)反应中。结果表明:采用酸掺杂原位合成制备得到的多级孔SAPO34分子筛与SAPO34分子筛的拓扑结构(CHA型)相同;多级孔SAPO34分子筛结晶度有所下降,比表面积、孔容有所增加;在活化温度550℃、反应温度450℃、载气流量30 mL/min、甲醇重时空速(WHSV)为2.0 h^(-1)、常压条件下,制备得到的0.5OASAPO34分子筛具有较优的催化性能,其催化寿命为570 min,与SAPO34分子筛原粉相比,提高了210 min,低碳烯烃(乙烯、丙烯)选择性为88.78%,与SAPO34分子筛原粉相比,低碳烯烃选择性基本保持一致。Acid was added to the molecular sieve synthesis mother liquor using an in-situ synthesis method,and the hierarchical SAPO-34 molecular sieve with an hourglass-like surface was successfully prepared.The properties of molecular sieves were analyzed by X-ray diffraction(XRD),scanning electron microscope(SEM),physical adsorption(BET),X-ray fluorescence(XRF),NH3 temperature programmed desorption(NH3-TPD),synchronous thermal analyzer(TG)and applied to methanol to olefin(MTO)reaction.Results showed that the CHA topological structure of the hierarchical SAPO-34 molecular sieve prepared by aid-doped in-situ synthesis was the same as that of SAPO-34 molecular sieve.The hierarchical SAPO-34 molecular sieve had a microporous-mesoporous or microporous-mesoporous-large pore multi-stage channel composite structure.The molecular sieve crystallinity decreased,while the specific surface area and pore volume increased.Under the conditions of activation temperature 550℃,reaction temperature 450℃,carrier gas flow rate 30 mL/min,weight hourly space velocity(WHSV)2.0 h^(-1),normal pressure,the 0.5OA-SAPO-34 molecular sieve had better catalytic performance.The catalytic life was 570 min,which was improved by 210 min compared with SAPO-34 molecular sieve original powder.The selectivity of light olefins(ethylene and propylene)was 88.78%,which was basically consistent with that of SAPO-34.

关 键 词：原位合成法 多孔级SAPO34分子筛 酸掺杂 氢氟酸 乙二酸 甲醇制烯烃 

分 类 号：TQ426.6[化学工程]