合成气制低碳烯烃串联反应中Zn-Al氧化物的制备及性能  

Study on preparation and catalytic performance of Zn-Al oxides for tandem reaction of syngas conversion into light olefins

作　　者：李保珍 孟凡会[1] 王丽娜[1] 李忠[1] LI Bao-zhen;MENG Fan-hui;WANG Li-na;LI Zhong(Taiyuan University of Technology,State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan 030024,China)

机构地区：[1]太原理工大学省部共建煤基能源清洁高效利用国家重点实验室,山西太原030024

出　　处：《燃料化学学报（中英文）》2023年第1期111-119,共9页Journal of Fuel Chemistry and Technology

基　　金：山西省自然科学基金(202103021224073);山西省重点研发计划(国际科技合作)(201803D421011)资助。

摘　　要：以工业拟薄水铝石为铝源,通过微波辅助蒸发诱导自组装(M-EISA)法制备了一系列不同Zn/Al原子比的Zn-Al氧化物,并与SAPO-18分子筛物理混合后考察其催化合成气制低碳烯烃(C_(2)^(=)-C_(4)^(=))反应性能。采用X射线衍射(XRD)、透射电镜(TEM)、N_(2)吸附-脱附、CO和H_(2)程序升温脱附(CO-TPD、H_(2)-TPD)、X射线光电子能谱(XPS)等进行表征。M-EISA法制备的Zn-Al氧化物随Zn/Al原子比的增加,比表面积和孔容逐渐下降,平均孔径先增大后降低。与浸渍(IP)法制备的ZnAl-IP相比,Zn/Al原子比为1∶2的ZnAl_(2)O_(x)样品中Zn分散度高,形成的ZnAl_(2)O_(4)尖晶石结构产生了更多的氧空位。催化结果表明,M-EISA法制备的Zn-Al样品活性随Zn/Al原子比的增加而先增加后减小,(C_(2)^(=)-C_(4)^(=))选择性逐渐降低。ZnAl_(2)O_(x)样品的CO转化率最高(34.8%),且反应50 h未见明显失活,催化性能明显优于ZnAl-IP样品。A series of Zn-Al oxides with different Zn/Al atomic ratios were prepared by the microwave-assisted evaporation-induced self-assembly(M-EISA)method,using industrial pseudo-boehmite as aluminum source.The prepared Zn-Al oxides were physically mixed with SAPO-18 zeolite and applied in tandem reaction for direct conversion of syngas to light olefins(C_(2)^(=)-C_(4)^(=))X-ray diffraction(XRD),transmission electron microscopy(TEM),N_(2) adsorption-desorption,CO and H_(2) temperature-programmed desorption(CO-TPD,H_(2)-TPD)and X-ray photoelectron spectroscopy(XPS)were selected for characterization.As the increase of Zn/Al ratio,the specific surface area and pore volume of Zn-Al oxides gradually decreased,while the average pore diameter firstly increased and then decreased.Compared with the ZnAl-IP prepared by the impregnation(IP)method,the ZnAl_(2)O_(x) with the Zn/Al ratio of 1∶2 had a high dispersion of Zn and formed the ZnAl_(2)O_(4) spinel structure that produced more oxygen vacancies.The catalytic results showed that the activity of Zn-Al samples prepared by M-EISA method firstly increased and then decreased as the Zn/Al ratio rose,while the(C_(2)^(=)-C_(4)^(=))selectivity gradually decreased.ZnAl_(2)O_(x) sample exhibited the highest CO conversion of 34.8%and almost no obvious deactivation after 50 h reaction,furthermore,its catalytic performance was much better than that of ZnAl-IP sample.

关 键 词：合成气转化 低碳烯烃 Zn-Al氧化物 双功能催化剂 微波辅助蒸发诱导自组装法 

分 类 号：O643.3[理学—物理化学]