以廉价的钛酸丁酯为钛源制备TiO2柱层状铌酸

以HNb3O8为层板主体, 正癸胺为预支撑剂, 以钛酸丁酯为钛源, 采用逐步离子交换法制备出钛(IV)多聚阳离子柱撑的铌酸盐, 经在空气中高温焙烧后得到TiO2柱层状铌酸. 用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、N2吸附-脱附技术和透射电镜(TEM)对产物结构进行了表征. TiO2柱层状铌酸的层间距为1.39 nm, 柱高为0.63 nm, 比表面积为35 m2•g－1. 该层柱材料具有良好的热稳定性, 在823 K的空气气氛中焙烧处理后, 其层柱结构仍能保持. 与先前用异丙氧钛为钛源制备TiO2柱层状铌酸的研究结果进行对照可知, 以廉价的钛酸丁酯代替异丙氧钛作钛源是可行的. 证明Ti(IV)多聚阳离子中不含CH3COO—等有机基团, 该多聚阳离子物种的形式是Ti(OH)x(H2O)y]z＋.

Preparation of TiO2-Pillared HNb3O8: Tetrabutyl Titanate Used as a Cheap Titanium Source

Ti(IV) polycation-intercalated niobate was synthesized through a stepwise ion-exchange route, in which HNb3O8 was used as the layered host, n-decylamine as a preswelling agent, and tetrabutyl titanate (abbreviated to TBT) as a titanium source. After the Ti(IV) polycation-intercalated niobate was calcined at 723 K in air environment, TiO2-pillared HNb3O8 was given. X-ray diffraction (XRD), framework infrared spectra FT-IR, N2 adsorption-desorption technique and transmission electron microscopy (TEM) were employed to investigate the structure of the obtained products. Characterizations by XRD and N2 adsorption-desorption isotherms indicated that the TiO2-pillared HNb3O8 was a porous layered material with an interlayer distance (d010) of 1.39 nm, a pillar height of 0.63 nm and a BET specific surface area of 35 m2&;#8226;g－1. The TiO2-pillared solid was thermally very stable, and its layered structure could be retained up to 823 K. Combined with our previous studying work, it was found that TBT as well as titanium tetraisopropoxide (abbreviated as TIP) could be used as the precursor of TiO2 pillars. Apparently, the TBT is more practicable than TIP since the latter is very costly and the former relatively cheap. It was demonstrated that the Ti(IV) polycation intercalated in the interlayers of the layered niobate contain no CH3COO－ and other organic groups, and thus it can be inferred that the Ti(IV) polycations have a formula of Ti(OH)x(H2O)y]z＋, in which x, y, and z are variables.