添加剂辅助合成纳米SAPO-34分子筛及其甲醇制烯烃反应性能  

Additive assisted synthesis of nano-sized SAPO-34 zeolite and its methanol to olefin reaction performance

作　　者：刘闯 李相呈 王振东 LIU Chuang;LI Xiangcheng;WANG Zhendong(State Key Laboratory of Green Chemical Engineering and Industrial Catalysis,Sinopec(Shanghai)Research Institute ofPetrochemical Technology Co.,Ltd.,Shanghai 201208,China)

机构地区：[1]中石化(上海)石油化工研究院有限公司绿色化工与工业催化国家重点实验室,上海201208

出　　处：《石油化工》2023年第11期1513-1518,共6页Petrochemical Technology

基　　金：国家自然科学基金项目(21972168)。

摘　　要：以四乙基氢氧化铵为有机结构导向剂及二环己胺(DCHA)为添加剂,合成了纳米尺寸SAPO-34分子筛,利用XRD、SEM、N2吸附-脱附、NH3-TPD考察了合成条件对分子筛结构与性能的影响。表征结果显示,添加一定量的DCHA可抑制晶体的生长,但添加过多会生成杂晶。在n(SiO_(2))∶n(Al_(2)O_(3))=0.40、180℃、晶化时间3.0 d的条件下,n(DCHA)∶n(Al_(2)O_(3))=0.20时合成的SAPO-34-0.20为晶体尺寸100 nm左右的纳米晶体,相比常规SAPO-34分子筛,晶体尺寸更小、酸强度适中、外比表面积和总孔体积更大。甲醇制烯烃(MTO)评价实验结果表明,添加DCHA合成的SAPO-34分子筛的MTO反应寿命较常规SAPO-34分子筛提高近1倍,且双烯选择性更高,显示较好的应用前景。Nano-sized SAPO-34 zeolites were synthesized by using tetraethylammonium hydroxide as organic structure directing agent and dicyclohexylamine(DCHA)as additive.The effects of synthsis conditions on the structure and performance of SAPO-34 zeolites were characterized by XRD,SEM,N2 adsorption-desorption and NH3-TPD.The results show that adding a certain amount of DCHA can inhibit the growth of crystals,but adding too much will generate heterocrystals.Under the conditions of n(SiO_(2))∶n(Al_(2)O_(3))=0.40,180℃,crystallization time 3.0 d and n(DCHA)∶n(Al_(2)O_(3))=0.20,SAPO-34-0.20 nanocrystals are obtained with a particle size of about 100 nm,which display smaller particle size,moderate acid strength,larger external surface area and total pore volume compared with conventional SAPO-34 zeolites.The methanol to olefins(MTO)evaluation experiment results indicate that the MTO reaction life of SAPO-34 zeolite synthesized by adding DCHA is nearly twice that of conventional SAPO-34 zeolite,and its selectivity to ethylene and propylene is higher,indicating good application prospects.

关 键 词：纳米SAPO-34分子筛 二环己胺 添加剂 甲醇制烯烃 

分 类 号：TQ426.95[化学工程]