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Study On Preparation Of TS-1 Film And Its Catalytic Properties In Epoxidation Of Allyl Chloride

Posted on:2007-02-28Degree:MasterType:Thesis
Country:ChinaCandidate:Y ZhouFull Text:PDF
GTID:2121360212480364Subject:Chemical processes
Abstract/Summary:PDF Full Text Request
Titanium silicalite-1 (TS-1) powder was synthesized via in situ hydrothermal method and characterized by XRD, FT-IR, FT-Raman, UV-Vis, and SEM. The results showed that the molar ratios of TEOS/TBOT and TPAOH/TEOS in the synthesis solution were important for the crystallinity, the framework Ti content and the content and category of extraframework Ti of TS-1. The catalytic property of TS-1 was evaluated in the epoxidation of allyl chloride (ACH) and H2O2. The catalytic activity of TS-1 improved with increasing the crystallinity and the framework Ti content. The deactivated TS-1 can be regenerated by calcination at 833 K. The main reason for the deactivation of TS-1 was the deposition of impurities in the ACH material and byproducts. And the minor reason was a little loss of framework Ti.TS-1 films were prepared on five supports via in situ hydrothermal method. The effects of the character and shape of the supports, the composition of the synthesis solution, the crystallization conditions and the growth times on the structure and the morphology of TS-1 films were investigated by XRD, FT-IR and SEM. It was found that it was easy to form TS-1 film on the rough, flat, porous supports, and the crystals of TS-1 film could come into the SiO2 pellet supports which had the similar property with the TS-1 film to form a transitional layer. The crystal size and the uniformity of TS-1 films were closely related with the compositions of the synthesis solution and the crystallization conditions. The optimized condition was as follow: molar ratio of TEOS: TBOT: TPAOH: H2O at 1: 0.04: 0.15: 100, the crystallization temparature at 170°C and the crystallization time at 96 h. With increasing the growth times, the crystallinity, the uniformity and the thickness of TS-1 films would increase, and the crystal flaws would decrease.Finally, the effects of the supports, the composition of the synthesis solution and the growth times on the catalytic activity of TS-1 films were investigated in the epoxidation of ACH and H2O2 in a fixed bed reactor. The results showed that the catalytic activity and stability were higher over secondary growth TS-1 films than others in our experiments. The conversion of ACH and the selectivity to epichlorohydrin were 85 % and 49 %, respectively.
Keywords/Search Tags:TS-1 powder, TS-1 film, epoxidation, allyl chloride, H2O2, epichlorohydrin
PDF Full Text Request
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