NH3处理的HY分子筛催化甲醛异丁烯Prins缩合反应  

Formaldehyde and isobutene condensation via Prins reaction on HY zeolites treated with NH3

作　　者：刘瑶 徐禄禄 张维萍[1] LIU Yao;XU Lulu;ZHANG Weiping(State Key Laboratory of Fine Chemicals,School of Chemical Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China)

机构地区：[1]大连理工大学化工学院精细化工国家重点实验室,辽宁大连116024

出　　处：《精细化工》2020年第10期2069-2075,共7页Fine Chemicals

基　　金：国家自然科学基金(21673027)。

摘　　要：对HY分子筛进行高温NH3处理,制备了一系列含氮样品。利用XRD、元素分析、29Si MAS NMR、NH3-TPD、CO2-TPD和TG等技术对NH3处理后样品的结构、酸碱性和反应后积碳量进行了深入表征。考察了其催化甲醛与异丁烯经Prins缩合制3-甲基-3-丁烯-1-醇(MBO)的催化性能,评价了反应条件及不同气氛氮化催化剂对反应性能的影响。结果表明,在230℃、4 h条件下,以含水体积分数为5%的氨气为氮源制备的催化剂(用量5%,以多聚甲醛的质量为基准,下同)对MBO的选择性达到89%,产率达到82%。并且反应后积碳量从未氮化HY催化剂上的27.0%显著下降到氮化催化剂上的4.3%。样品的酸性和碱性表征结果表明,NH3处理后的Y分子筛酸量减少而中等强度的碱量增加,从而抑制了副反应进行,提高了MBO的选择性,降低了积碳量。A series of nitrogen-containing samples were prepared by treating HY zeolites with NH3 at high temperature.Their structures,acidity and basicity as well as the coke contents after reaction were characterized by means of XRD,elemental analysis,29Si MAS NMR,NH3-TPD,CO2-TPD and TG techniques.Their catalytic performances in the formaldehyde-isobutene Prins condensation to prepare 3-methyl-3-buten-1-ol(MBO)were evaluated.The effects of reaction conditions and samples nitridated under different atmosphere on the catalytic performances were investigated.The results showed that under the conditions of 230℃and 4 h,for the catalyst(dosage was 5%,based on the mass of paraformaldehyde,the same below)prepared with NH3 containing 5%volume fraction water treatment,the selectivity and yield of MBO were up to 89%and 82%,respectively.Moreover,the coke content of HY zeolite after reaction was 27.0%,while that of the nitridated sample was only 4.3%.The acidity and basicity characterization results of the samples indicated that NH3 treatment led to the decrease of the acidic sites and increase of the medium-strong basic sites of Y zeolite,which inhibited the side reactions and enhanced MBO selectivity.Meanwhile,the coke content decreased obviously on the nitridated sample due to its fewer acid sites and appropriate amount of basic sites.

关 键 词：Y分子筛 氮化 碱催化 3-甲基-3-丁烯-1-醇 Prins缩合反应 催化技术 

分 类 号：TQ426.6[化学工程]