不同酸性SAPO-34分子筛的制备及其催化合成气制低碳烯烃性能研究  

Synthesis of SAPO-34 zeolites with different acidity and their catalytic performance in syngas to olefins reaction

作　　者：魏晓娜 李文双 陈诗通 刘志强 李丽 王闯 Wei Xiaona;Li Wenshuang;Chen Shitong;Liu Zhiqiang;Li Li;Wang Chuang(Chia Tai Energy Materials(Dalian)Co.,Ltd.,Dalian 116000,Liaoning,China)

机构地区：[1]正大能源材料(大连)有限公司,辽宁大连116000

出　　处：《工业催化》2022年第2期41-47,共7页Industrial Catalysis

基　　金：辽宁省自然科学基金项目(20180550316)。

摘　　要：以三乙胺为模板剂,改变初始合成凝胶中n(SiO_(2))∶n(Al_(2)O_(3))调变SAPO-34分子筛的酸性质,合成了不同Si引入量的SAPO-34分子筛,并分别与ZnCrAlO_(x)氧化物进行混合制备双功能催化剂,研究了其催化CO加氢直接合成低碳烯烃的性能。通过XRD、SEM、NH_(3)-TPD、XRF以及N_(2)吸附-脱附对分子筛的结构、形貌、酸性质和元素组成进行了表征。评价结果表明,在合成的催化剂中,酸性较弱的SP34-0.2分子筛制备的双功能催化剂(ZnCrAlO_(x)/SP34-0.2)表现出最高的低碳烯烃选择性,并且催化剂在经过300 h的连续反应后,低碳烯烃选择性仍维持在81%左右,表明该双功能催化剂具有良好的稳定性。SAPO-34 zeolites with different Si content were synthesized by changing SiO_(2)/Al_(2)O_(3) molar ratio in the starting gel to adjust their acidity.Bifunctional catalysts were prepared by mixing the synthesized zeolites with ZnCrAlO_(x) oxide and their catalytic performance in CO hydrogenation to light olefins was investigated.The structure,morphology,acidity and elemental composition of the zeolites were characterized by XRD,SEM,NH_(3)-TPD,XRF and N_(2) adsorption-desorption.The results showed that the bifunctional catalyst(ZnCrAlO_(x)/SP34-0.2)prepared by SP34-0.2 zeolites with weaker acidity exhibited the highest selectivity to light olefins,remaining at about 81%after 300 hours,indicating that the bifunctional catalyst has excellent activity stability.

关 键 词：催化剂工程 合成气制低碳烯烃 硅引入量 酸性 分子筛 ZnCrAlO_(x)氧化物 

分 类 号：O643.3[理学—物理化学] TQ426.94[理学—化学]