Preparation of Pt-Ru Hydrophobic Catalysts and Catalytic Activities for Liquid Phase Catalytic Exchange Reaction

Pt/C and PtRu/C catalysts with different ratios of Pt to Ru were synthesized, using ethylene glycol as both the dispersant and reducing agent at 1-2 MPa by microwaveassisted method. The catalysts were characterized by XRD, TEM and XPS. The mean particle sizes of the Pt/C and PtRu/C catalysts were 1.9-2.0 nm. Pt and Ru existed as Pt（0）, Pt（Ⅱ）, Pt（Ⅳ）, Ru（0） and Ru（Ⅳ） for Pt-Ru/C catalysts, respectively. The facecentered cubic structure of the active mental particles would be changed upon the addition of Ru gradually. Then polytetrafluoroethylene and carbon supported Pt and Pt-Ru catalysts were supported on foamed nickel to obtain hydrophobic catalysts. The catalytic activity was increased for liquid phase catalytic exchange （LPCE） when uniform Pt based hydrophobic catalysts was mixed into appropriate Ru. Hydrogen isotope exchange reaction occurs between hydration layer （H2O）nH+（ads）（n≥2） and D atoms due to intact water molecules being on Pt surface for LPCE. Water molecules have a tendency to dissociate to OH （ads） and H （ads） on metal Ru surface, and there is the other reaction path for Pt-Ru binary catalysts, which is probably the main reason of the increase of the catalytic activity of the hydrophobic Pt-Ru catalyst.