文献类型：期刊文献

中文题名：用氟化氢-三乙胺复合模板剂合成SAPO-34分子筛

英文题名：Synthesis of SAPO-34 Molecular Sieve Using Hydrogen Fluoride and Triethylamine as Composite Template

作者：刘红星[1];谢在库[2];张成芳[1];陈庆龄[2]

机构：[1]华东理工大学化工工艺研究所,上海200237;[2]中国石油化工股份有限公司上海石油化工研究院,上海201208

年份：2003

卷号：24

期号：4

起止页码：279

中文期刊名：催化学报

收录：CSTPCD;;Scopus;北大核心:【北大核心2000】；CSCD:【CSCD2011_2012】；

语种：中文

中文关键词：氟化氢;三乙胺;复合模板剂;合成;SAPO-34分子筛;甲醇;低碳烯烃;乙烯;丙烯;选择性;催化剂

外文关键词：SAPO 34 molecular sieve, composite template, hydrogen fluoride, triethylamine, methanol, olefin

摘要：采用X射线衍射、扫描电镜、氨吸附红外光谱及核磁共振等表征手段 ,研究了以氟化氢 三乙胺为复合模板剂合成的SAPO 34分子筛 .结果表明 ,相对于用三乙胺模板剂合成的样品 ,用氟化氢 三乙胺复合模板剂合成的样品结晶度高 ,晶粒小 ,分子筛的酸量低 ,骨架中硅结构单一 ,比表面积和孔体积较大 .以氟化氢 三乙胺复合模板剂合成的分子筛 ,在催化甲醇制低碳烯烃反应中结焦速率降低 。
It is a new technique to synthesize SAPO 34 molecular sieve using cheap triethylamine (Et 3N) as the template, and the selectivity of this molecular sieve for ethene and propene can be improved further. In this paper, the effect of adding HF in Et 3N solution on the structure and catalytic performance of SAPO 34 was studied. XRD results reveal that the addition of HF decreases the defects in the crystal lattice of SAPO 34, which is proved by the two distinct double peaks at 2 θ =26°and 31° and other higher characteristic peaks. SEM results show that the SAPO 34 sample prepared by using pure Et 3N as the template has both big and small crystallization centers,but the addition of HF can avoid the formation of the big crystallization centers and help to form the uniform small SAPO 34 crystals. From the NH 3 IR results, we can draw the conclusion that the use of HF decreases the number of the surface acid sites of B acid and L acid. The NMR results show that HF changes the chemical enviroment of Si in SAPO 34 and makes SAOP 34 form simple Si structure with only SiAl 4 and without Si island as the number of the surface acid sites decreases. The mechanism of the effect of HF is that HF dissolves the Si source and Al source in the initial gel to produce chelates, and form more crystal nucleus quickly, then it disperses the directions of the centralizating of the materials in the initial gel and forms uniform small SAPO 34 crystals. HF may form fluoride and occlude the pores of SAPO 34, thus the molecular sieve sample has a larger surface area and a larger pore volume. The catalyst performance evaluation shows that the SAPO 34 sample with HF Et 3N as the composite template has a lower coking rate and a slightly higher selectivity for ethylene and propylene in methanol to olefin reaction.