摘要
在TS-2分子筛胶液制备过程中,添加了络合稳定剂H2O2。实验分析表明:钛酸四丁酯与H2O2形成过氧化钛物种,可以有效避免锐钛矿TiO2形成,提高骨架钛含量,在高温条件下晶化仍能得到催化性能较好的TS-2分子筛。利用丙烯环氧化反应对TS-2分子筛进行了考评,H2O2的转化率可达94%,H2O2生成PO的选择性可达97%。反应体系的酸碱性对环氧化产物分布影响显著,碱性物质的加入可以显著提高PO的选择性,抑制PO和溶剂发生的副反应,但是过量的碱性添加物会造成TS-2分子筛的失活。
H2O2 was used to prepare the TS-2 gel. Peroxytitanate was formed from the reaction of tetra-n-butyl titanate （TBOT） and H2O2, which had the advantages of high Ti content in molecular sieve framework and preventing the formation of anatase TiO2. In addition, TS-2 prepared at an elevated temperature still had good catalytic performance. The epoxidation of propylene was used to test the catalytic performance of TS-2. The reaction conversion based on H2O2 was 94% while the propylene oxide （PO） selectivity reached as high as 97%. The pH value of reaction medium influenced the composition of the product remarkably. The PO selectivity increased significantly if a small amount of base was added into the reaction medium. But a larger amount of base easily inhibited the activity of TS-2.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2007年第7期1828-1833,共6页
CIESC Journal
关键词
TS-2分子筛
水热晶化
丙烯环氧化
TS-2 molecular sieve
hydrothermal crystallization
propylene epoxidation
