Properties of Pt/SiO2 catalysts modified by a heteropoly acid (HPA) were studied in oxidative dehydrogenation of propane with an O-2 and H-2 mixture. The catalysts were characterized with N-2 adsorption, IRS, XPS, and HAADF-STEM coupled with EDX, and the possibility for Pt and HPA to be highly dispersed and well-mixed on the silica surface has been shown. In the presence of O-2 and H-2, propene could be obtained at temperatures as low as 150 degrees C, but heating to 200 degrees C provided much better selectivity (up to 94-96% at propane conversion of 2-4%). The process probably proceeded through oxidation of propane with peroxo species to C-3-alcohols on Pt sites, followed by dehydration of the alcohols on the acid sites of HPA. The catalytic properties were strongly dependent both on the feed composition (the C-3 H-8/H-2/O-2/N-2 ratio) and on the composition of catalysts, optimum HPA loading being 20-30 wt.% at 0.2-1 wt.% of Pt. Under optimal operating conditions, a space time yield of propene was at a level of 420 gkg(cat)(-1)h(-1) without a tendency to decline with time on stream. (C) 2014 Elsevier B.V. All rights reserved.