In this study, MWNT and alumina nanopowder were used as a ruthenium catalyst support for the conversion of carbon monoxide to methane. Metal foam structures were employed to support such catalytic systems, offering in...In this study, MWNT and alumina nanopowder were used as a ruthenium catalyst support for the conversion of carbon monoxide to methane. Metal foam structures were employed to support such catalytic systems, offering interesting possibilities for commercial applications due to low-pressure drop; excellent flow characteristic and heat transfer properties. Prior to the ruthenium impregnation, the MWNT surface was initially modified by means of metal cation activation and surface adsorption of anionic surfactant. The decoration processes using both surface modifications promoted the deposition of ruthenium with a mean 2 nm diameter. The use of nickel as a nucleating center enhanced the Ru nanoparticle density on the CNT surface compared to the Ru/CNT catalyst prepared by excess solution impregnation. As a reducing agent, ethylene glycol completely converted Ru2＋ to Ru0as confirmed by an EDS/TEM analysis. Among the prepared catalysts, Ru/AI203-CNTs prepared by Ni2＋ activation showed the best performance for the hydrogenation reaction. This is interpreted in terms of the higher ruthenium nanoparticle exposure on the nanostructured catalyst, as a result of the better MWNT dispersion in the MWNT/Al2O3 mixture.展开更多
文摘In this study, MWNT and alumina nanopowder were used as a ruthenium catalyst support for the conversion of carbon monoxide to methane. Metal foam structures were employed to support such catalytic systems, offering interesting possibilities for commercial applications due to low-pressure drop; excellent flow characteristic and heat transfer properties. Prior to the ruthenium impregnation, the MWNT surface was initially modified by means of metal cation activation and surface adsorption of anionic surfactant. The decoration processes using both surface modifications promoted the deposition of ruthenium with a mean 2 nm diameter. The use of nickel as a nucleating center enhanced the Ru nanoparticle density on the CNT surface compared to the Ru/CNT catalyst prepared by excess solution impregnation. As a reducing agent, ethylene glycol completely converted Ru2＋ to Ru0as confirmed by an EDS/TEM analysis. Among the prepared catalysts, Ru/AI203-CNTs prepared by Ni2＋ activation showed the best performance for the hydrogenation reaction. This is interpreted in terms of the higher ruthenium nanoparticle exposure on the nanostructured catalyst, as a result of the better MWNT dispersion in the MWNT/Al2O3 mixture.
