Effects of Preparation on the Properties of Niobia-Alumina Binary Oxides

摘要

Niobia/Alumina (Nb2O5/Al2O3) mixed oxides and SiO2- supported Nb2O5/Al2O3 binary oxides were prepared over a wide composition range. The mixed oxides were prepared by coprecipitation and the supported oxides were synthesized by incipient wetness impregnation. All of the binary oxides were calcined (500 C) in oxygen and had a further high temperature (1000 C) ramp in flowing helium, to determine if the materials were stable. All oxides were found to be amorphous after calcination, while the mixed oxides formed crystallites after the high temperature ramp. By using Hammett indicators and titrating with n-butyl-amine, the binary oxides all showed high acid strength and acidity. The catalytic activities of these materials were investigated by the 1-butene isomerization reaction. Keywords: Niobia-Alumina binary oxides, Mixed oxide, Surface-Phase oxide, Supported oxide, Supported binary oxide. (jes)