Platinum on carbonaceous supports for glycerol hydrogenolysis: Support effect

Metal vapor synthesis (MVS) technique was applied to generate Pt-nanoparticles of different size (< 1.3 nm and 2.5 nm) deposited onto carbonaceous supports, mainly characterized by a different surface area. The supported catalysts were employed in the glycerol hydrogenolysis reaction carried out under basic reaction conditions at 433 and 453 K to obtain 1,2-propanediol as the main liquid product. Comparison of the composition of the liquid- and gas-phase products obtained by the different catalysts showed a clear dependence of aqueous-phase reforming, water-gas shift reaction activity as well as 1,2-propanediol chemoselectivity on the degree of Pt-sintering occurring on different carbon supports. High resolution transmission electron microscopic and X-ray powder diffraction studies carried out on as-synthesized and recovered heterogeneous catalysts provided clear evidences that a high surface area carbon support, such as Ketjen Black EC-600JD, notably retards nanoparticle aggregation.