摘要
用水热法于140—200℃下在 Si-P-Al-iPr_2NH(二异丙胺)-H_2O 体系中合成了 SAPO-11分子筛。在 H_2O/Al+P+Si=12.5,iPr_2NH/Al+P+Si=0.25的特定条件下,产生 SAPO-11的纯相区域为:P_2O_5/Al_2O_3=0.43—1.25,SiO_2/Al_2O_3=0—1.0,SiO_2/P_2O_5=0—1.0。在 H_2O/Al+P+Si=12.5,Al∶P∶Si=4∶5∶1的情况下,当 iPr_2NH/P_2O_5=1.0—1.5时,产物为纯 SAPO-11。SAPO-11是在弱酸性介质中产生的,当反应混合物的初始 pH=4.5—7.0时,产物为纯 SAPO-11。在200℃下晶化,由无定形胶直接转变为 SAPO-11,而在170℃和140℃下,无定形胶首先转变成未知的介稳相,然后再转变为 SAPO-11。
Novel molecular sieve of SAPO-11 can be prepared by carrying out hydrother-real synthesis in a system of Si-P-Al-(iPr)_2NH-H_2O at 140—200℃.Under thespecific conditions of H_2O/(Al+P+Si)=12.5 and (iPr)_2NH/(A1+P+Si)=0.25,theappropriate composition zone of the reactants for the formation of pure SAPO-11is defined by P_2O_5/Al_2O_3=0.43-1.25,SiO_2/Al_2O_3=0-1.0 and SiO_2/P_2O_5,=0-1.0.With (iPr)_2NH/P_2O_5=1.0-1.5,pure SAPO-11 is obtained even when Al:P:Si=4:5:1 and H_2O/(Al+P+Si)=12.5.The influence of pH of the reaction mixture onthe characteristics of product phase is very obvious.Under the above specificconditions,with the initial pH 4.5-7.0 pure SAPO-11 is obtained.The effect oftemperature on the crystallization process of SAPO-11 is also investigated.Under200℃,SAPO-11 crystallized directly from the amorphous gel,but under 170℃and 140℃,SAPO-11 crystallized from the gel through an unknow crystal phase.
出处
《石油化工》
CAS
CSCD
北大核心
1989年第8期503-508,共6页
Petrochemical Technology
基金
国家自然科学基金
