Dehydrogenation of propane over spinel-type gallia–alumina solid solution catalysts

Dehydrogenation of propane to propylene in the presence or absence of carbon dioxide was performed over a series of mixed GaxAl10−xO15 oxides (with x varying from 0 to 10) synthesized through an alcoholic coprecipitation pathway. Among the various compositions of GaxAl10−xO15, the maximum activity was observed for image. Whereas the same tendency was observed for the specific activity normalized by BET surface area, significantly enhanced stability was achieved for Ga2O3–Al2O3 with higher aluminum content. A correlation between the NH3-TPD results and the initial activity for GaxAl10−xO15 reveals that a high population of surface acid sites related to tetrahedral Ga3+ cations is important to achieving high activity. The specific interaction between Ga2O3 and Al2O3 due to the formation of spinel-type γ-Ga2O3–Al2O3 solid solutions is suggested to play a key role in the dispersion and distribution of surface gallium sites, which makes GaxAl10−xO15 composites highly active and stable for the reaction.