摘要
以 N ,N ,N′,N′-四甲基 -1 ,6-己二胺 ( TMHD)为模板剂 ,采用水热法在 Al2 O3 -P2 O5-Si O2 体系中合成了 SAPO-56分子筛 .固定模板剂和水 ,得到 Al-Si-P三元体系相图 .当原料物质的量比为 0 .5<n( Si O2 ) /n( M) <0 .7( M=Si O2 +Al2 O3 +P2 O5) ,0 .1 5<n( Al2 O3 ) /n( M) <0 .4及 0 .1 <n( P2 O5) /n( M) <0 .3时 ,出现SAPO-56合成的纯相区 .固定合成凝胶中硅、铝、磷和水的量 ,模板剂的用量改变对合成影响较大 .n( TMHD) /n( P2 O5)≥ 2时 ,产物是纯 SAPO-56.用 XRD,SEM,IR,DTA-TG和吸附等方法研究了产物的物化性能 .结果表明 ,SAPO-56分子筛具有较好的热稳定性 (骨架坍塌温度为 1 1 50℃ )和较大的水吸附量( 41 % ) .SAPO-56分子筛催化剂对甲醇转化制烯烃反应表现出了良好的催化活性和较高的 C2 和 C3 烯烃选择性 .
The molecular sieve SAPO 56 has been synthesized hydrothermally using N,N,N′,N′ tetramethyl 1,6 dihexane as template. In the Al 2O 3 SiO 2 P 2O 5 medium, phase diagram of SAPO 56 was obtained. Pure phase region of SAPO 56 appeared in the range of 0.5<n(SiO 2)/n(M)<0.7(M=SiO 2+Al 2O 3+P 2O 5), 0.15<n(Al 2O 3)/n(M)<0.4 and 0.1<n(P 2O 5)/n(M)<0.3. The effect of template amount on the synthesis of SAPO 56 was also investigated. Provided that other compositions (Si, Al, P and H 2O) was fixed, it presented pure SAPO 56 crystal in the ratios of n(TMHD)/n(P 2O 5)≥2. The properties of SAPO 56 were characterized by XRD, SEM, TG DTA, IR and adsorption technique which suggested that SAPO 56 had a good thermal stability and large water adsorption capacity. In the methanol to olefins reaction, SAPO 56 catalyst exhibited a high activity and selectivities to C 2, C 3 olefins.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2001年第6期991-994,共4页
Chemical Journal of Chinese Universities
