Various magnesium aluminum oxides [Mg(Al)O] were prepared by physical mixing, hydrothermal, and solvothermal method (with and without calcination) and employed as supports for bimetallic PtSn catalysts for propane dehydrogenation. The use of non-calcined Mg(Al)O-sv obtained from the solvothermal method led to the highest Pt dispersion, the lowest fraction of strong acid sites, and the lowest metallic tin species as well as coke content. Unlike the other catalysts that gradually deactivated with time-on-stream, the PtSn/Mg(Al)O-sv maintained high propylene yield (similar to)26.9% during 5 h reaction time without any sign of catalyst deactivation. The improved catalyst performances were attributed not only to the high surface area flower-like nanosheet structure of the Mg(Al)O-sv but also the uniform Mg-O-Al bonding and high Al/Mg atomic ratio on the catalyst surface as confirmed by the XPS results.