The effects of V and Ce concentrations(each varying in the 0-100%range)in vanadia-ceria multiphase systems are investigated for synthesis gas production via thermochemical redox cycles of CO_(2) and H_(2)O splitting c...The effects of V and Ce concentrations(each varying in the 0-100%range)in vanadia-ceria multiphase systems are investigated for synthesis gas production via thermochemical redox cycles of CO_(2) and H_(2)O splitting coupled to methane partial oxidation reactions.The oxidation of prepared oxygen carriers is performed by separate and sequential CO_(2) and H_(2)O splitting reactions.Structural and chemical analyses of the mixed-metal oxides revealed important information about the Ce and V interactions affecting their crystal phases and redox characteristics.Pure CeO_(2) and pure V_(2)O_(5) are found to offer the lowest and highest oxygen exchange capacities and syngas production performance,respectively.The mixed-oxide systems provide a balanced performance:their oxygen exchange capacity is up to 5 times higher than that of pure CeO_(2) while decreasing the extent of methane cracking.The addition of 25%V to CeO_(2) results in an optimum mixture of CeO_(2) and CeVO4 for enhanced CO_(2) and H_(2)O splitting.At higher V concentrations,cyclic carbide formation and oxidation result in a syngas yield higher than that for pure CeO_(2).展开更多
基金This study used the facilities and the scientific and technical assistance at the Centre for Advanced Microscopy at the Australian National UniversityWe also acknowledge the technical assistance provided by Colin Carvolth and Kevin CarvolthThis work was supported by the Australian Research Council(ARC Future Fellowship FT140101213 by W.Lipinski).
文摘The effects of V and Ce concentrations(each varying in the 0-100%range)in vanadia-ceria multiphase systems are investigated for synthesis gas production via thermochemical redox cycles of CO_(2) and H_(2)O splitting coupled to methane partial oxidation reactions.The oxidation of prepared oxygen carriers is performed by separate and sequential CO_(2) and H_(2)O splitting reactions.Structural and chemical analyses of the mixed-metal oxides revealed important information about the Ce and V interactions affecting their crystal phases and redox characteristics.Pure CeO_(2) and pure V_(2)O_(5) are found to offer the lowest and highest oxygen exchange capacities and syngas production performance,respectively.The mixed-oxide systems provide a balanced performance:their oxygen exchange capacity is up to 5 times higher than that of pure CeO_(2) while decreasing the extent of methane cracking.The addition of 25%V to CeO_(2) results in an optimum mixture of CeO_(2) and CeVO4 for enhanced CO_(2) and H_(2)O splitting.At higher V concentrations,cyclic carbide formation and oxidation result in a syngas yield higher than that for pure CeO_(2).
