Effect Factors In Synthesis Process Of TS-1 Zeolite

The nano-scale TS-1 is synthesized by using self-made tetrapropylammonium hydroxide (TPAOH) solution as the template, tetraethyl orthosilicate (TEOS) as Si source and tetrabutyl orthotitanate(TBOT) as the Ti source. The synthesis conditions are investigated on effect of its synthesis and catalytic performance for propene epoxidation, including the source of TPAOH, concentration of TPAOH and so on. The samples are characterized by XRD, IR, UV-Vis and TEM. The catalytic performance of nano-scale TS-1 samples is evaluated by the reaction of synthesis of propylene oxide (PO) from propylene and hydrogen peroxide. The results indicat that the repeated experiment of magnify synthesis nano-scale TS-1 is well, the length of crystaline part always is 100～200 nm, its catalytic performance is good, the conversion of hydrogen peroxide (X_H2O2) and the selectivity of propene oxide (S_PO) reaches 97.0% and 96.4 % respectively.The micro-TS-1 samples are synthesized by using tetrapropylammonium bromide (TPABr) solution as the template, ethylamine as alkali source, silica sol as Si source, titanium tetrachloride (TiCl₄) as Ti source, add seeds. The synthesis conditions are investigated on effect of its synthesis and catalytic performance for propene epoxidation, including different seeds, magnify synthesis. The results indicate that TS-1 is synthesized by using nano-TS-1 seed, X_H2O2 reaches 95.0%and S_PO reaches 85.7 % respectively. Micro-TS-1 of magnify synthesis, the higher S_PO, but X_H2O2 is the same.The micro-TS-1 is modified by TPAOH, Na₂SO₃. The modification conditions are investigated, including the source of TPAOH, the ratio of micro-TS-1 and modification agent. The results show that the framework of TS-1 is not changed obviously after modified by TPAOH, but pore which dimeter is about 0.5 nm and 1.5 nm is more, the optimal modification conditions of TPAOH are following:100 g TS-1:0.024 mol TPAOH:23 mol H₂O, modification temperature 170℃, modification time 48 h. TS-1 is modified by Na₂SO₃, results show that modified TS-1 could disable Lewis acid, the quality of Na₂SO₃ is feasible, S_PO is the most high, and X_H2O2 changes unconspicuous. The optimal modification conditions of Na₂SO₃ are as follows: 100 g TS-1: 0.3 g Na₂SO₃, whisk for 6 h in room temperature.