Synthesis, characterization and catalytic properties of titania-silica catalysts
Synthesis, characterization and catalytic properties of titania-silica catalysts
复制标题
DOI：
10.1016/s0927-7757(02)00002-x
复制
发表时间：
2002-07-30
影响因子：
5.2
通讯作者：
Yamaguchi, T
中科院分区：
文献类型：
--
作者：
Mohamed, MM;Salama, TM;Yamaguchi, T
The preparation of titania doped (0.63 - 3.2 mmol g(-1)) silica (TiO2/SiO2) was described together with a mixed oxide sample (TiO2-SiO2) at a nominal molar ratio near to 1. These materials were thoroughly characterized by XRD, N-2 adsorption at 76 K and ammonia adsorption measurements as well as FTIR spectroscopy. The activity of the materials towards 1-butene isomerization was also tested. FTIR results showed a band at 612 cm(-1) attributed to bulk TiO2 phase, in the doped 3.2 mmol g(-1) TiO2/SiO2 Sample, that was paralleled to an exhibited perturbation for the SiO2 bands in the low frequency region, specifically those at 470 and 808 cm(-1). The former band was similarly obtained in the TiO2-SiO2 sample, with a lower decrease in intensity, together with the appearance of a new band at 948 cm(-1) attributed to Ti-O-Si linkages. This deed indicated the decrease in population of Ti-O-Ti bridges in the mixed oxide sample. FTIR spectra of adsorbed D2O established the presence of different types of titania hydroxyl groups (3615 and 3520 cm(-1)) that were composed during desorption of water from the titania surface. The activity towards 1-butene isomeriztion was found to increase gradually, in the doped samples, to achieve its maximum at the titania loading 3.2 mmol g(-1), however, a tremendous decrease was obtained for the mixed oxide sample. This behavior was correlated with the acidity of the samples. The dependence of the reaction on either Ti-O-Ti or Ti-O-Si sites was evaluated and discussed. (C) 2002 Published by Elsevier Science B.V.
