The effect of the synthesis method over the catalytic behavior was investigated in Pt and PtSn catalysts. Catalysts synthesized using the one-step sol-gel method (OSSGM) were compared with those synthesized by conventional impregnation in the n-heptane reforming reaction at 500 degrees C and 1 atm. showing that the one-step sol-gel synthesis enhances both the activity and the resistance to deactivation by coking. The formation of coordinatively unsaturated aluminum (Al-v) in the materials is promoted by the OSSGM, and it can be related to the increment in both their acidity and their platinum dispersion. Therefore, the bifunctionality of the catalysts, measured as the metal/acid site ratio (Psi parameter), was also correlated to the Al-v species. Higher values of Psi implied it higher resistance to deactivation, higher rates of toluene production. and an inhibition of benzene induced by the OSSGM,