SUPPORTED PtRu CATALYSTS FROM A MIXTURE OF PLATINUM AND RUTHENIUM ACETYLACETONATE: CHARACTERIZATION AND ACTIVITY FOR ETHYLENE HYDROGENATION

Supported bimetallic PtRu catalysts were prepared by adsorption of a mixture of Pt(acac)2 and Ru(acac)3 (acac = acetylacetonate) in toluene, onto γ-Al2O3 and MgO and the organic ligands were removed by heat in H2 flow at 300 o C for 2 h. The nature of metal and interaction with each support was studied by temperature-programmed reductive decomposition (TPRD) and infrared (IR) spectroscopy. TPRD data did not indicate any contact between Pt and Ru atoms on both supports after the treatment. Ethylene hydrogenation over PtRu/γ-Al2O3 and PtRu/MgO catalysts were carried out at 1 atm from -50 to -9 o C. The temperature dependence of ethylene hydrogenation of PtRu/γ-Al2O3 and PtRu/MgO prepared from acac precursors gave apparent activation energy 8.1 ± 0.1 and 6.0 ± 0.1 kcal/mol, respectively.