Introduction:Coke formation continues to be an important challenge for Pt-based catalysts during propane dehydrogenation (PDH) . Boron promotion drastically reduces coke formation on nickel during steam reforming and on cobalt during Fischer-Tropsch synthesis. DFT calculations and catalyst characterization indicate that reduced boron atoms selectively block step and/or subsurface sites, thus preventing nucleation and growth of deactivating carbon .In this work, boron is introduced to enhance the catalytic performance of Pt/γ-Al O catalysts during PDH. A series of catalysts with different boron loadings was prepared following various impregnation sequences. Detailed characterization and DFT calculations help identify boron's location and state (alloy/amorphous oxide). Results: XB-γ-Al O support materials (X=wt.%B) were prepared via wet impregnation of H BO onto commercial γ-Al O . Three different synthesis routes were followed: (a) Pt/XB-γ-Al O catalysts were prepared via wet impregnation of H PtCl onto XB-γ-Al O . (b) 1B/Pt-γ-Al O was prepared via wet impregnation of H BO onto Pt/γ-Al O i.e., an inverse sequential impregnation. (c) Pt-1B-γ-Al O was prepared by co-impregnation. Pt/γ-Al O was prepared as a reference. The platinum loading was fixed at 3wt.% to facilitate characterization and obtain B/Pt (mol) ratios from 1-10.Effects of boron loading and impregnation sequence were investigated during short-term (20 min) PDH tests at 600 C and a C H /H ratio of one. Unlike with nickel and cobalt, the promoting effect of boron was only observed when boron was introduced before the active metal. The Pt/1B-γ-Al O catalyst showed only a minor reduction in activity during the short-term experiment but achieved a 2.6-fold reduction in the amount of deposited carbon for an optimal loading of 1wt.% B. Long-term experiments (12 hr) confirmed the improved stability and selectivity of Pt/1B-γ-Al O , (Fig. 1a) with a 3.2-fold reduction in deposited carbon and an increase in propylene selectivity from 92 to 98%. TPO-profiles (Fig. 1b) of spent catalysts show that boron promotion eliminates and reduces the low-and high-temperature carbon oxidation peaks, respectively. Propylene decomposition experiments on pure and boron-modified γ-Al O relate the low-temperature peak to carbon formed on the support.