Direct propane dehydrogenation (PDH) has emerged as one of the most promising approaches to produce propylene. Pt is a commercially used metal for PDH and Sn is the most commonly used promoter for Pt catalysts. The PDH reaction is known to be structure-sensitive, meaning its kinetics depend on the structure of the Pt. However, the optimal type, loading, and impact of the promoter remain unclear due to the lack of guiding principles. We have developed PtSn loaded Al2O3 catalysts with various Pt:Sn ratio, which showed very different propylene formation rate and deactivation rate. Here we apply for the Pt L3 edge and Sn K edge QXAFS study combined with Raman and UV-Visible spectroscopies. This study will measure the evolution of Pt and Sn coordination under H2 activation, propane dehydrogenation and regeneration. Compared with different Pt:Sn ratio will determine the optimal geometric structure of Pt and Sn, providing fundamental understanding to improve catalysts performance.