Fibrous titanium silicalite (FTS-1) zeolite has been prepared from titanium silicalite (TS-1) particles that were less than 120 nm in diameter. The formation of FTS-1 was mainly affected by the particle size of the TS-1 zeolite. FTS-1 is formed by both capillary force and dehydroxylation among the TS-1 particles during the drying and evaporation process of the dispersed TS-1 particles in aqueous solution. The average length and the aspect ratio (length/diameter) of FTS-1 are 2.2 and mm 50-70, respectively. The obtained FTS-1 shows a two-dimensionally aligned surface that is affected by the treatment of dispersed TS-1 particles in aqueous solution. 29Si MAS n.m.r. spectra showed that the concentration of the hydroxyl group on the surface of TS-1 particles was decreased after the formation of FTS-1 and was reduced continuously up to 750°C with calcination. This suggests that the condensation reaction of hydroxyl groups on the surface of TS-1 particles occurs by drying and heat treatment. After calcination at 750°C, FTS-1 still exhibited characteristics of MFI-type structure with orthorhombic symmetry. It showed distinctive secondary pores due to the aggregation of TS-1 particles. This method of FTS-1 formation may suggest a new method for the preparation of various types of zeolites.
Bibliographical noteFunding Information:
We are grateful to Dr. W.G. Scherer (DuPont Co.) for his helpful discussions, to Dr. S. Nakata (Chiyoda Co.) for measuring the *%i izllAS n.m.r., and to Dr. J.G. Kim (Soonchunhyang University) for measuring the TEM. This study was carried out by financial support from Daelim Engineering Co.
All Science Journal Classification (ASJC) codes
- Environmental Science(all)