Enhanced activity of spinel-type Ga2O3-Al2O3 mixed oxide for the dehydrogenation of propane in the presence of CO2

Catalytic performance of a series of Ga(2)O(3)-Al(2)O(3) mixed oxides prepared by alcoholic-coprecipitation method for the dehydrogenation of propane in the presence of CO(2) was investigated. It is shown that the combination of Ga and Al oxides greatly improved the performance of the Ga(2)O(3)-based materials for catalytic dehydrogenation of propane, with the highest performance attainable at a Ga(2)O(3)-Al(2)O(3) catalyst with a 20 mol% aluminum content. While the same tendency was observed for the specific activity normalized by BET surface area, significantly enhanced stability was achieved for Ga(2)O(3)-Al(2)O(3) with higher aluminum content. X-ray diffraction (XRD) revealed that a homogeneous spinel-type Ga(2)O(3)-Al(2)O(3) solid solution is uniformly formed by substitution of Ga(3+) for Al(3+) in the Al(2)O(3) lattice. The enhanced activity of Ga(2)O(3)-Al(2)O(3) mixed oxides was accounted for by the abundance of surface weak acid sites due to the synergetic interaction between Ga(2)O(3) and Al(2)O(3) in the solid solution systems.