INFLUENCE OF TERMAL TREATEMNT ON THE CATALYTIC ACTIVITY OF SHAPE-SPECIFIC RUTHENIUM NANOCATALYSTS

Ruthenium metal particles can be catalytically active for hydrogenation of organic compounds. However, supported Ru nanoparticles can be deactivated by processes such as sintering, leaching of active components, oxidation of noble metal nanoparticles, deposition of inactive metals, or surface poisoning via formation of a metal oxide layer or adsorption of impurities from solvents and reagents. Thermal treatment is an option for reactivation of Ru nanoparticles immobilized on SiO2 (Ru/SiO2), utilized as a nanocatalysts in chemical reactions. The effects of thermal treatment on the catalytic activity of shape-specific 0.1 wt% Ru/SiO2 were investigated for cyclohexene hydrogenation. Varying the temperature and time of the activation treatment demonstrated the effect of such treatments on the activity of shape-specific Ru nanocatalysts. The highest activity (100%) was obtained when the catalyst was activated by calcination in a furnace under the mildest reductive conditions studied here (temperature: 200 oC for 1 hour). HRTEM revealed only minor deformation of the shape-specific Ru particles and minimal aggregation under these conditions.

کلیدواژه ها:

Shape-specific Ru nanocatalysts ، cyclohexene hydrogenation ، thermal treatment