纳米薄层SAPO-5分子筛的离子热合成及催化性能  

Ionothermal synthesis of SAPO-5 molecular sieve nanosheets and its catalytic performances

作　　者：张峻维 段维婷 赵新红[1] ZHANG Junwei;DUAN Weiting;ZHAO Xinhong(School of Petrochemical Engineering,Lanzhou University of Technology,Lanzhou 730050,Gansu,China)

机构地区：[1]兰州理工大学石油化工学院,甘肃兰州730050

出　　处：《精细化工》2020年第3期547-554,共8页Fine Chemicals

基　　金：国家自然科学基金(21666019);甘肃省自然科学基金(17JR5RA124)。

摘　　要：以小剂量的丁二酸、氯化胆碱和四乙基溴化铵复配形成的低共熔混合物为溶剂和模板,以水热法合成的纳米薄层SAPO-5分子筛作为晶种,使用离子热法在微波加热功率为400 W、温度为180℃和晶化时间为20 min的条件下,高效合成了具有六角花瓣状的纳米薄层SAPO-5分子筛。采用XRD、SEM、N2物理吸/脱附和NH3-TPD对合成样品的物相、形貌、孔结构和酸性进行了分析。结果表明,所合成的样品SC2-T180-t20-P400是一种同时含有微孔-介孔-大孔结构的多级孔SAPO-5分子筛,其外表面积高达85m2/g。分子筛产物中无机物的原子利用率达到88%。该样品在苯与苯甲醇的烷基化反应中,苯甲醇转化率和二苯甲烷选择性分别达到99.9%和94.0%,表现出比传统水热法合成的纳米薄层SAPO-5催化剂更为优异的催化性能。Hexagonal petal-like nanosheets SAPO-5 molecular sieve were effectively synthesized by ionothermal method under the conditions of microwave heating power of 400 W,temperature of 180℃ and crystallization time of 20 min,in which a low-dosage eutectic mixture composed of succinic acid,choline chloride and tetraethyl ammonium bromide was used as solvent and template,nanosheets SAPO-5 molecular sieve synthesized by hydrothermal method was acted as crystal seeds.The phase,morphology,pore structure and acidity of the synthesized samples were analyzed by XRD,SEM,N2 physical adsorption/desorption and NH3-TPD techniques.The results showed that the synthesized sample SC2-T180-t20-P400 was a hierarchically porous SAPO-5 molecular sieve with micro-meso-macroporous structure inside,and its external surface area was up to 85 m2/g.The atomic utilization efficiency of inorganic substances in molecular sieve products reached 88%.Most importantly,the conversion rate of benzyl alcohol and the selectivity of diphenylmethane in the alkylation reaction between benzene and benzyl alcohol on SC2-T180-t20-P400 reached 99.9%and 94.0%,respectively,showing SC2-T180-t20-P400 had better catalytic performance than the traditional hydrothermally synthesized counterpart.

关 键 词：SAPO-5 纳米薄层 多级孔 晶种 离子热合成 催化技术 

分 类 号：O614[理学—无机化学] O643.36[理学—化学]