双模板剂法控制SAPO－34分子筛的晶粒尺寸

Adjusting the Crystallite Size of SAPO-34 Molecular Sieve by the Dual Template Method

分别在ＮＥｔ＿３，ＴＥＡＯＨ和ＴＥＡＯＨ－ＮＥｔ＿３双模板剂存在下合成了磷酸硅铝分子筛ＳＡＰＯ－３４．考察了模板剂的组成对ＳＡＰＯ－３４的晶粒尺寸、比表面、热稳定性和对甲醇转化反应催化性能的影响。实验表明，采用ＴＥＡＯＨ－ＮＥｔ＿３双模板剂法，能有效地控制ＳＡＰＯ－３４的晶粒尺寸，以微量的ＴＥＡＯＨ与ＮＥｔ＿３为双模板剂合成的大晶粒ＳＡＰＯ－３４分子筛。

Silicoaluminophosphate molecular sieve SAPO-34 was synthesized with trithyl amine(NEt3),tetraethylammonium(TEAOH), and the mixture of NEt3 and TEAOH as the template respectively. The influences of the composition of template on the crystallite size, BET surface area and thermal stability of SAPO- 34 were investigated, The experimental results show that the crystallite size was reduced and BET surface area was increased when the mole ration of TEAOH vs.NEt3 in the dual template system was increased, However, the thermal stability of SAPO-34 was not changed substantially when the template composition was altered. The effect of template's composition was also studied on the catalytic properties for the conversion of methanol to light olefins. The results of catalytic test indicated that the selctivity of increased remarkably when minute TEAOH was added into NEt3 template in the synthesis of SAPO-34 molecular sieve.