TY - JOUR
T1 - Effect of the type of preparation on the properties of titania/silicas
AU - Toba, Makoto
AU - Mizukami, Fujio
AU - Niwa, Shu-ichi
AU - Sano, Tsuneji
AU - Maeda, Kazuyuki
AU - Annila, Arto
AU - Komppa, Veikko
PY - 1994
Y1 - 1994
N2 - Titania/silicas were prepared by four methods: (i) complexing-agent assisted sol—gel, (ii) coprecipitation, (iii) hydrogel kneading and (iv) xerogel kneading. The properties of these titania/silicas were investigated by thermal gravimetry and differential thermal analysis (TG-DTA) X-ray powder diffraction, solid-state magic angle spinning nuclear magnetic resonance (MAS NMR), ammonia temperature programmed desorption (TPD) and nitrogen adsorption. Of the four methods, the complexing-agent assisted sol—gel method gave the most homogeneous titania/silicas. Their TiOSi bond formation, acidities, and specific surface areas depended on completing agents used in the preparations and the Ti/Si ratios of raw materials. In contrast, the kneading titania/silicas were heterogeneous and their properties did not depend on the Ti/Si ratio. The dependence of properties of coprecipitated titania/silicas on their Ti/Si ratio were intermediate between those of complexing-agent assisted sol—gel and kneading.
AB - Titania/silicas were prepared by four methods: (i) complexing-agent assisted sol—gel, (ii) coprecipitation, (iii) hydrogel kneading and (iv) xerogel kneading. The properties of these titania/silicas were investigated by thermal gravimetry and differential thermal analysis (TG-DTA) X-ray powder diffraction, solid-state magic angle spinning nuclear magnetic resonance (MAS NMR), ammonia temperature programmed desorption (TPD) and nitrogen adsorption. Of the four methods, the complexing-agent assisted sol—gel method gave the most homogeneous titania/silicas. Their TiOSi bond formation, acidities, and specific surface areas depended on completing agents used in the preparations and the Ti/Si ratios of raw materials. In contrast, the kneading titania/silicas were heterogeneous and their properties did not depend on the Ti/Si ratio. The dependence of properties of coprecipitated titania/silicas on their Ti/Si ratio were intermediate between those of complexing-agent assisted sol—gel and kneading.
U2 - 10.1016/0304-5102(94)00040-9
DO - 10.1016/0304-5102(94)00040-9
M3 - Article
VL - 91
SP - 277
EP - 289
JO - Journal of Molecular Catalysis
JF - Journal of Molecular Catalysis
SN - 0304-5102
IS - 2
ER -