Bimetallic Pt-Sn nanocluster from the hydrogenolysis of a well-defined surface compound consisting of [([tbnd]AlO[sbnd])Pt(COD)Me] and [([tbnd]AlO[sbnd])SnPh3] fragments for propane dehydrogenation.

• Pt-Sn/θ-Al 2 O 3 catalysts were prepared from Surface Organometallic Chemistry concept. • Pt-Sn clusters around 0.75 nm are uniformly distributed at the surface of θ-Al 2 O 3. • Pt-Sn catalyst exhibits high performance in propane dehydrogenation reaction. The bimetallic Pt-Sn catalysts are known to be the most efficient ones for propane dehydrogenation reaction; however, the synthesis of bimetallic Pt-Sn nanocluster (below 1 nm) with an alloy structure still remains a formidable challenge. An approach for the controllable synthesis of Pt-Sn nanocluster based on Surface Organometallic Chemistry on oxide concept is developed here, which involves two basic steps: the sequential grafting of Pt(COD)Me 2 and HSnPh 3 at the surface of dehydroxylated θ-Al 2 O leading to the formation of well-defined bimetallic surface compound consisting of [(AlO)Pt(COD)Me] and [(AlO)SnPh 3 ] fragments, and the hydrogenolysis of this surface compound under a mild condition giving rise to the ultra-small bimetallic Pt-Sn cluster around 0.75 nm. The achieved Pt-Sn/θ-Al 2 O 3 catalysts exhibit high activity, selectivity and stability in propane dehydrogenation to propylene. [ABSTRACT FROM AUTHOR]