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以丁二酸/癸二酸、氯化胆碱与四乙基溴化铵复配形成的低共熔体作为溶剂和模板剂,采用微波-离子热法合成了SAPO-5分子筛。考察了晶化温度、前驱物的种类及低共熔混合物的种类对多级孔SAPO-5分子筛形貌的影响。采用XRD、SEM、N_2物理吸脱附对合成产物的结构、形貌和孔结构进行了表征。SEM结果表明,铝源为异丙醇铝时,其样品为六棱柱晶体和纳米粒子团聚物,铝源为碱式乙酸铝时,样品为具有不同长宽比的柱状晶体。N_2物理吸脱附表明,癸二酸部分替换丁二酸在无氢氟酸条件下合成的样品F1,介孔体积较大,为0.297cm~3/g。SEM、N_2物理吸脱附分析表明,该分子筛是一种同时含有微孔和介孔结构的磷酸铝分子筛。将3种具有不同孔结构的催化剂用于苯与苄醇的烷基化反应中,F1表现出较高的催化活性,苄醇的转化率达到91%。
SAPO-5 molecular sieve was synthesized by microwave-ionothermal method using succinic acid / sebacic acid, choline chloride and tetraethylammonium bromide as eutectic as solvent and templating agent. The effects of crystallization temperature, precursor type and eutectic mixture morphology on the morphology of SAPO-5 molecular sieves with multiple pores were investigated. The structure, morphology and pore structure of the synthesized product were characterized by XRD, SEM and N 2 physisorption. The SEM results show that when the aluminum source is aluminum isopropylate, the samples are hexagonal prism crystals and nanoparticle agglomerates, and when the aluminum source is basic aluminum acetate, the samples are columnar crystals with different aspect ratios. N 2 physisorption showed that the sebacic acid partially replaced the succinic acid synthesized hydrofluoric acid sample F1, mesoporous volume larger, 0.297cm ~ 3 / g. SEM and N_2 physical adsorption desorption analysis showed that the molecular sieve is a kind of aluminum phosphate molecular sieve containing both microporous and mesoporous structures. Three kinds of catalysts with different pore structures were used in the alkylation of benzene with benzyl alcohol. F1 showed higher catalytic activity and the conversion of benzyl alcohol reached 91%.