TPAOH-NH3·H2O溶液处理TS-1/SiO2对丙烯环氧化反应影响  

Effect TPAOH-NH_3·H_2O solution treatment on catalytic performance of TS-1/SiO_2 for propylene epoxidation

作　　者：韩鑫鹏 李昊阳[1] 王骁 孟凡军 陈恒宝 孙超 王亚权[1] Han Xinpeng;Li Haoyang;Wang Xiao;Meng Fanjun;Chen Hengbao;Sun Chao;Wang Yaquan(Key Laboratory for Green Chemical Technology of Ministry of Education,College of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学化工学院,教育部绿色化学工艺重点实验室,天津300072

出　　处：《工业催化》2018年第5期36-42,共7页Industrial Catalysis

基　　金：国家自然科学基金(21276183)资助项目

摘　　要：将SiO_2负载的钛硅分子筛(TS-1/SiO_2)用四丙基氢氧化铵和氨水混合溶液处理并用于催化丙烯环氧化制环氧丙烷反应。结果表明,混合溶液处理的钛硅分子筛比用四丙基氢氧化铵或氨水单独处理的样品具有更好的催化性能。随着混合碱中氨水浓度从0.01 mol·L-1增加到0.03 mol·L-1,附着在分子筛表面的二氧化硅载体消失,可能被溶解并再结晶到分子筛表面。同时,在此溶解再结晶过程中,分子筛内部产生许多介孔,使其催化性能显著提升,而二氧化硅表面酸性位被消除。四丙基氢氧化铵和氨水协同作用产生大的介孔,有利于高分子量副产物扩散出催化剂粒子,导致催化剂稳定性明显提升而催化活性和选择性不受影响。Titanium silicate-1(TS-1)/SiO 2 extrudates were post-treated with NH 3·H 2 O and tetrapropyl ammonium hydroxide(TPAOH),studied in propylene epoxidation with hydrogen peroxide in fixed-bed reactor.The results demonstrated that the TS-1 treated with mixed bases showed better catalytic performance than that treated with NH 3·H 2 O or TPAOH alone.When NH 3·H 2 O concentration increasing from 0.01 mol·L-1 to 0.03 mol·L-1 in post treatment,particles of SiO 2 supports disappeared,which might be dissolved and recrystallized on TS-1 crystals.At the same time,TS-1 crystals also pass dissolution and recrystallization process with large number of mesopores formed inside.Catalytic properties of TS-1 greatly enhanced,while acid sites from SiO 2 surface depleted.Large pores created by synergetic effect of ammonia and TPAOH facilitated diffusion of high molecular weight by products resulting in appreciable improvement of catalyst stability while activity and selectivity not influenced.

关 键 词：催化剂工程 钛硅分子筛 丙烯环氧化 氨水 后处理 催化剂稳定性 

分 类 号：TQ426.6[化学工程] TQ424.25