【摘要】 以K2CO3、Nb2O5和TiO2为原料,经高温固相反应制得KTiNbO5,进一步与HCl溶液反应后得到HTiNbO5。HTiNbO5经用长链有机胺预支撑,再与含Ti(IV)聚合阳离子溶液反应,所得产物在空气气氛中焙烧后制备出高比表面钛铌复合氧化物。它是一类多孔材料,其BET比表面积达80~100 m2.g-1。测试了该复合氧化物以及在该复合氧化物上负载B2O3后所得担载型催化剂在环己酮肟气相贝克曼重排反应中的催化性能。当B2O3负载量为7.31%(质量分数)时,环己酮肟转化率(~100%)在4.5 h内无明显改变,反应进行6 h后,转化率仍高于85%;己内酰胺选择性接近或超过90%且在整个反应过程中基本不变。更多还原

【Abstract】 KTiNbO₅ was synthesized by heating a stoichiometric mixture of K₂CO₃,La₂O₃,and Nb₂O₅,and HTiNbO₅ was obtained by ion exchange of KTiNbO₅ in HCl solution.HTiNbO₅ was pre-expanded by long-chain alkylamine,then reacting with a solution containing Ti（IV） polycations,followed by calcining the obtained precursor in air,two titanoniobium composite oxides（designated as HTNO） with a high specific surface area were prepared.The products were porous materials,and their BET surface areas were 80 ～ 100 m²·g^-1.The vapor phase Beckmann rearrangement reaction of cyclohexanone oxime was studied with HTNO and B₂O₃/HTNO as catalysts.The B₂O₃/HTNO catalyst with B₂O₃ loading of 7.31 wt % exhibited 100% conversion of the oxime with ε-caprolactam selectivity near or beyond 90%.The conversion was no significant change within 4.5 h and still higher than 85% after 6 h.更多还原