采用ICP-AES,TEM,XRD,FT-IR和FT-Raman等技术研究了TS-1分子筛的晶化过程.结果表明,TS-1分子筛的晶化过程从无定形SiO2颗粒开始生长,以SiO2颗粒的外表面为晶核不断发展,晶化过程的第一小时内主要以无定形的SiO2-TiO2共凝胶颗粒存在,1 h后开始迅速形成TS-1晶粒,TS-1晶粒的生成与无定形SiO2的消失同时发生,8 h后基本上完成TS-1分子筛的成长,结晶度达到95%,形成完善的MFI拓扑学结构;晶化过程初期基本上未见到锐钛矿TiO2生成.随着晶化时间的推移,少量锐钛矿TiO2开始出现.样品的总钛含量在8 h附近达到最大值,Ti4+基本上进入分子筛骨架.值得一提的是,在晶化过程的第一小时内,MFI拓扑学结构尚未充分形成(红外光谱中无1 226和550 cm-1特征吸收峰),但在960 cm-1处发现较弱的红外特征吸收峰,说明960 cm-1谱峰不是TS-1分子筛所特有,它可能属于TS-1分子筛的Si-O-Ti键,也可能属于SiO2-TiO2共凝胶中的Si-O-Ti键.
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