Ethane,one of the key components of shale gas,is a valuable feedstock for the production of syngas(CO+H_(2))via the C-C bond cleavage during dry reforming of ethane(DRE)reaction.Selective catalysts are needed to direc...Ethane,one of the key components of shale gas,is a valuable feedstock for the production of syngas(CO+H_(2))via the C-C bond cleavage during dry reforming of ethane(DRE)reaction.Selective catalysts are needed to direct this reaction pathway against the competing C-H bond cleavage for ethylene formation.In this study,Fe,V and Rh oxides supported on TiO_(2)catalysts were prepared by impregnation method.The catalysts were tested for DRE with the main target of enhancing selectivity to syngas(CO and H_(2))and reducing byproducts(methane and ethylene)formation.The catalysts were characterized using X-ray diffraction,scanning electron microscopy,NH_(3)/CO_(2)temperature programmed desorption and H_(2)-temperature programmed reduction.Temperature programmed oxidation was utilized to characterize the coke contents of the spent catalysts.The catalysts were evaluated for DRE reaction in a fixed-bed reactor at the temperature range from 500℃to 650℃and CO_(2)/ethane ratio from 2:1 to 10:1(mol/mol).It was found that ethane conversion over the three catalysts increased in the order Rh/TiO_(2)>Fe/TiO_(2)>V/TiO_(2).Rh/TiO_(2)catalyst exhibited>99%ethane conversion,36%and 61%yields of H_(2)and CO,respectively,at 650℃and CO_(2)/ethane ratio of 5.0.The high conversion of ethane was mainly attributed to the enhanced dispersion of Rh oxides on the TiO_(2)support coupled with the balanced surface acidic and basic sites.The Rh catalyst facilitated C-C bond dissociation of ethane thereby forming methyl intermediates which then reacted with adsorbed CO_(2),thereby enhancing higher syngas production during DRE reaction.展开更多
文摘Ethane,one of the key components of shale gas,is a valuable feedstock for the production of syngas(CO+H_(2))via the C-C bond cleavage during dry reforming of ethane(DRE)reaction.Selective catalysts are needed to direct this reaction pathway against the competing C-H bond cleavage for ethylene formation.In this study,Fe,V and Rh oxides supported on TiO_(2)catalysts were prepared by impregnation method.The catalysts were tested for DRE with the main target of enhancing selectivity to syngas(CO and H_(2))and reducing byproducts(methane and ethylene)formation.The catalysts were characterized using X-ray diffraction,scanning electron microscopy,NH_(3)/CO_(2)temperature programmed desorption and H_(2)-temperature programmed reduction.Temperature programmed oxidation was utilized to characterize the coke contents of the spent catalysts.The catalysts were evaluated for DRE reaction in a fixed-bed reactor at the temperature range from 500℃to 650℃and CO_(2)/ethane ratio from 2:1 to 10:1(mol/mol).It was found that ethane conversion over the three catalysts increased in the order Rh/TiO_(2)>Fe/TiO_(2)>V/TiO_(2).Rh/TiO_(2)catalyst exhibited>99%ethane conversion,36%and 61%yields of H_(2)and CO,respectively,at 650℃and CO_(2)/ethane ratio of 5.0.The high conversion of ethane was mainly attributed to the enhanced dispersion of Rh oxides on the TiO_(2)support coupled with the balanced surface acidic and basic sites.The Rh catalyst facilitated C-C bond dissociation of ethane thereby forming methyl intermediates which then reacted with adsorbed CO_(2),thereby enhancing higher syngas production during DRE reaction.
