摘要
对ZSM-5烷基选择性的研究已有较多报道,但在提高对位选择性的同时,往往导致活性的损失,产生“反向效应”,本文试图用复合改性来探讨解决这种效应的可能性 1 实验部分 氢型分子筛加粘接剂成型(Hz),于873 K下通水蒸气处理(HZ·H_2O),采用浸渍法制得P或Mg改性催化剂,改性物的含量分别为4％P_2O_5(P_1HZ)、10％P_2O_5(P_2HZ)。
The effects on the properties of ZSM-5 zeolite modified by steam. H3PO4 and Mg(Ac)2 were studied. It is shown that middle strong acid sites were the active sites for ethyla-tion of toluene with ethanol. It is possible to cover the external surface acid sites selectively and keep the channel structure essentially by depositing an adequate amount of P and Mg on the steam-treated zeolite. This is assumed in favour of increasing the shape-selectivity .to remain the activity as the unmodified zeolite. In this case,the so called 'opposite effect' may be overcome. The modified catalyst P1Mg1HZ is stable at an average activity of 16- 5% with the 85% p-selectivity and >97% alkylation selectivity for 100 hours on streaming.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1991年第11期1535-1536,共2页
Chemical Journal of Chinese Universities
基金
国家自然科学基金
中山大学科学基金
