小晶粒、板状和多级孔结构SAPO-34分子筛的合成及其在甲醇制烯烃中的应用  

Synthesis of nano-sized,plate-like and hierarchical SAPO-34 zeolites and applications thereof for the methanol-to-olefin reactions

作　　者：陆贤[1] 丁佳佳 张玉贤[1] 刘红星[1] Lu Xian;Ding Jiajia;Zhang Yuxian;Liu Hongxing(Sinopec Shanghai Research Institute of Petrochemical Technology,Shanghai 201208,China)

机构地区：[1]中国石化上海石油化工研究院,上海201208

出　　处：《石油化工》2020年第4期321-326,共6页Petrochemical Technology

基　　金：国家重点研发计划项目(2016YFB0701100)。

摘　　要：为克服因常规SAPO-34分子筛的相对狭长孔道导致的严重扩散限制问题,采用不同的方法合成了小晶粒、板状形貌和多级孔结构的SAPO-34分子筛。利用XRD、SEM、N2吸附-脱附和NH3-TPD等手段对所合成的SAPO-34分子筛进行表征,并将其应用于甲醇制烯烃(MTO)反应中,研究了SAPO-34分子筛的晶粒尺寸、形貌及孔道结构对催化性能的影响。实验结果表明,虽然所制备的4种分子筛具有相近的酸性质,但相较于常规分子筛,小晶粒、板状形貌和多级孔结构的SAPO-34分子筛具有较小的晶粒尺寸、特殊的形貌及介/大-微孔道结构;将所制备的4种分子筛催化剂应用于MTO反应中,在反应温度为460℃、WHSV为3 h-1、系统压力为常压、原料为纯甲醇的条件下,多级孔结构试样的双烯选择性最高可达85.1%,同时催化剂具有较好的稳定性。To overcome the inherent diffusion drawbacks of conventional SAPO-34 zeolite caused by long and narrow channel,nano-sized,plate-like and hierarchical SAPO-34 zeolites were synthesized by different methods. The obtained samples were characterized by XRD,SEM,N2 adsorption-desorption and NH3-TPD,and were used as catalysts in methanol-to-olefin reactions. The effects of crystal size,morphology of particles and pore structure of SAPO-34 zeolites on the catalytic performances in methanolto-olefin(MTO) reactions were evaluated. The experimental results indicated that though having similar density of acid sites with conventional SAPO-34 zeolite,the prepared four nano-sized,plate-like and hierarchical SAPO-34 zeolites samples have smaller grain,special particle morphology and hierarchical structure with macro-meso-microporosity compared with the conventional sample,respectively. In MTO reactions,the ethylene and propylene selectivity of hierarchical sample can be up to 85.1%(experimental conditions:reaction temperature 460 ℃,WHSV 3h-1,atmospheric pressure and pure methanol as raw material),and the hierarchical sample also shows the higher stability in MTO reaction.

关 键 词：SAPO-34分子筛 小晶粒 板状 多级孔 甲醇制烯烃 

分 类 号：TQ426.6[化学工程]