摘要
采用Na2O-TiO2-Al2O3-SiO2-KF-H2O无机体系,在190℃、120h下水热合成出结晶性层状铝钛硅酸盐(Al-JDF-L1)。用XRD、SEM、低温N2吸附-脱附和多重EDX分析表征了产物的晶相、组成和孔结构。表征结果显示,Al-JDF-L1具有与层状钛硅酸盐JDF-L1相同的晶相、形貌结构和微孔吸附性能。当结晶产物的骨架Al/Ti原子比为0.07时,Al(Ⅲ)以AlO4四面体形式嵌入Al-JDF-L1晶体结构,形成单一相Al-JDF-L1层状晶体;当骨架Al/Ti原子比增至0.37时,Al-JDF-L1层状晶体是合成产物的主要晶相,并伴生六方结构的毛沸石竞争相。此外,1.78%(w)甲基纤维素辅助合成的Al-JDF-L1试样(骨架Al/Ti原子比为0.35)具有皱缩的表面层理结构和尺度分布较宽(2.4~35nm)的层间孔,其附加的BJH比表面积和孔隙率明显增加。
Novel crystalline alumino-titanosilicates with layered structure,namely microporous molecular sieves Al-JDF-L1,were hydrothermally synthesized at 190 ℃ for 120 h in Na2O-TiO2-Al2O3-SiO2-KF-H2O inorganic systems,and characterized by means of XRD,SEM,N2 adsorption-desorption and multiple EDX.The layered Al-JDF-L1 crystals showed the same crystal phase,morphological structure and microporous sorption capacity as layered titanosilicate JDF-L1,and the multiple EDX data concerning crystal compositions provided the evidence of aluminum substitution in the form of tetrahedron in Al-JDF-L1 when the Al/Ti atomic ratio of Al-JDF-L1 crystals was about 0.07.When the Al/Ti atomic ratio increased to 0.37,Al-JDF-L1 crystals as dominant phase formed with the intergrowth of a little competing hexagonal erionite.Furthermore,an isostructural analogue with Al/Ti atomic ratio 0.35 prepared with 1.78%(w) methyl cellulose-containing initial gel was confirmed to feature a wrinkled,laminated structure,which created additional mesoporosity with interlamellar distances of 2.4-35 nm and an increased BJH specific surface area.
出处
《石油化工》
CAS
CSCD
北大核心
2013年第6期597-603,共7页
Petrochemical Technology
基金
辽宁省自然科学基金项目(200922180)
国家自然科学基金项目(21171083)
关键词
水热合成
Al-JDF-L1分子筛
同晶取代
铝钛硅酸盐
层状结构
hydrothermal synthesis
Al-JDF-L1 molecular sieves
isomorphous substitution
alumino-titanosilicate
layered structure