摘要
以经过预先处理的ＢＺＳＭ－５为母体，采用气固相同晶取代方法制备Ｔｉ－ＳｉＺＳＭ－５沸石。研究处理方法对母体影响发现，单纯焙烧ＢＺＳＭ－５，由于非骨架Ｂ的产生及Ｎａ＋的驻留，Ｔｉ同晶取代难以发生；若进一步以ＨＣｌ处理，则不仅能将非骨架Ｂ及Ｎａ＋从沸石内部交换出来，还能起到深度脱Ｂ作用，为Ｔｉ的补入提供更多的活性位置，大幅提高取代效率。同时，温度也是影响取代效果的重要因素。以环己酮氨氧化为探针反应研究诸样品性能，发现以ｄｅ－［Ｂ］ＺＳＭ－５为母体，较高温度下制备的Ｔｉ－ＳｉＺＳＭ－５更具催化活性；沸石中Ｓｉ—ＯＨ的存在有利于反应中间物的吸附并提高环己酮转化率。
itanium silicalite TiSiZSM5 can be prepared by gassolid isomorphous substitution using pretreated BZSM5 as precursors.In the case of simple calcination of BZSM5,it is found that owing to the formation of extraframework boron and the stabilizing effect of Na+ in zeolite,isomorphous replacement of Ti is difficult to occur.However,further treatment of the calcinated BZSM5 with HCl to form de〔B〕ZSM5 can not only replace extraframework B and Na+,but also remove B from the depth of the zeolite.Temperature is another important factor influencing the efficiency of Ti replacement.In the ammoxidation of cyclohexanone,it is found that TiSiZSM5 prepared from de〔B〕ZSM5 at high substitution temperature is catalytically more active,and the existence of SiON in zeolites is beneficial to the adsorption of intermediate and thus to a higher conversion of cyclohexanone.
出处
《石油化工》
CAS
CSCD
北大核心
1998年第5期319-323,共5页
Petrochemical Technology
基金
辽宁省博士启动基金
中石化-国家自然科学基金
