A method for metal dispersion measurement in bimetallic Pt-Sn/Al2O3 catalysts using a combination of nonactivated and activated H-2/O-2 chemisorptive titrations has been attempted. Fractions of dispersed, unalloyed Pt, Pt(U), alloyed Pt, Pt(A) and alloyed Sn, Sn(A) may be determined by this method. The Pt(A) and Sn(A) contents of the catalysts correspond to a mole ratio (Pt/ Sn) approximate to 1, (for catalysts containing 0.4 wt% Pt and Sn content ranging such that the atomic ratio of Sn to Pt varies from 0.25-8, in steps) indicating possible formation of an alloy phase, PtSn (1:1 mole basis). Turnover numbers for dehydrogenation of n-dodecane indicate that Sn increases overall dispersion of Pt by dilution/ ensemble effects. Increasing the Sn:Pt ratio to 16 results in decreased dispersion. Typical trends in H-2/O-2 uptakes with respect to titration cycles for bimetallic Pt-Sn catalysts vis a vis monometallic Pt/Al2O3 catalysts are discussed.