双模版剂法制备SAPO-5和SAPO-34分子筛

Synthesis of SAPO-5 and SAPO-34 Molecular Sieves by Dual-template Method

以二乙胺和四乙基氢氧化铵为混合模版剂,采用水热法合成了SAPO-5和SAPO-34分子筛,并用XRD,SEM,XRF,NH3-TPD等手段对其表征,以氧化苯乙烯重排反应为探针反应评价其活性。分别讨论了加料顺序和晶化升温模式对合成SAPO-5和SAPO-34的影响。结果表明,改变加料顺序和晶化升温模式时,在原料和合成物料配比不变的条件下可以分别合成出纯相的SAPO-5和SAPO-34分子筛。在氧化苯乙烯重排反应中,由于SAPO-34含有强酸位,会产生大量聚合物,使得苯乙醛的选择性较低,而只含有弱酸位的SAPO-5表现出较好的活性和选择性。

SAPO-5 and SAPO-34 Molecular Sieves were synthesized with diethylamine and tetraethyl ammonium hydroxide as dual-template under hydrothermal conditions. The products were characterized by XRD,SEM,XRF and NH3-TPD. The catalysts were tested in the styrene oxide rearrangement reaction.The influence of feeding order and heating mode were investigated in detail. The results indicate that pure SAPO-5 and SAPO-34 can be synthesized with different feeding order and heating mode,in condition of the same sources and same ratio of the reactants. The SAPO-34 catalyst with strong acid sites had lower selectivity to phenylacetaldehyde because of the formation of oligomers,while the SAPO-5 catalyst with only weak acid sites exhibited better catalytic performance in the styrene oxide rearrangement reaction.