Advanced oxygen carrier plays a pivotal role in various chemical looping processes,such as CO_(2)splitting.However,oxygen carriers have been restricted by deactivation and inferior oxygen transferability at low temper...Advanced oxygen carrier plays a pivotal role in various chemical looping processes,such as CO_(2)splitting.However,oxygen carriers have been restricted by deactivation and inferior oxygen transferability at low temperatures.Herein,we design an Fe-Ov-Ce-triggered phase-reversible CeO_(2)−x·Fe·CaO↔CeO_(2)·Ca_(2)Fe_(2)O_(5)oxygen carrier with strong electron-donating ability,which activates CO_(2)at low temperatures and promotes oxygen transformation.Results reveal that the maximum CO_(2)conversion and CO yield obtained with 50 mol%CeO_(2)−x·Fe·CaO are,respectively,426%and 53.6 times higher than those of Fe·CaO at 700℃.This unique multiphase material also retains exceptional redox durability,with no obvious deactivation after 100 splitting cycles.The addition of Ce promotes the formation of the Fe-Ov-Ce structure,which acts as an activator,triggers CO_(2)splitting,and lowers the energy barrier of C═O dissociation.The metallic Fe plays a role in consuming O_(2)−lattice transformed from Fe-Ov-Ce,whereas CaO acts as a structure promoter that enables phase-reversible Fe0↔Fe3+looping.展开更多
基金supported by the National Key R&D Program of China(2022YFE0105900)the National Natural Science Foundation of China(52436006,52476144,52311530339,42441835)the Innovation-Driven Project of Central South University(2023ZZTS0721).
文摘Advanced oxygen carrier plays a pivotal role in various chemical looping processes,such as CO_(2)splitting.However,oxygen carriers have been restricted by deactivation and inferior oxygen transferability at low temperatures.Herein,we design an Fe-Ov-Ce-triggered phase-reversible CeO_(2)−x·Fe·CaO↔CeO_(2)·Ca_(2)Fe_(2)O_(5)oxygen carrier with strong electron-donating ability,which activates CO_(2)at low temperatures and promotes oxygen transformation.Results reveal that the maximum CO_(2)conversion and CO yield obtained with 50 mol%CeO_(2)−x·Fe·CaO are,respectively,426%and 53.6 times higher than those of Fe·CaO at 700℃.This unique multiphase material also retains exceptional redox durability,with no obvious deactivation after 100 splitting cycles.The addition of Ce promotes the formation of the Fe-Ov-Ce structure,which acts as an activator,triggers CO_(2)splitting,and lowers the energy barrier of C═O dissociation.The metallic Fe plays a role in consuming O_(2)−lattice transformed from Fe-Ov-Ce,whereas CaO acts as a structure promoter that enables phase-reversible Fe0↔Fe3+looping.
