The formation and qualification of redox sites in transition metal oxides are always the active fields related to electronics, catalysis, sensors, and energy-storage units. In the present study, the temperature depend...The formation and qualification of redox sites in transition metal oxides are always the active fields related to electronics, catalysis, sensors, and energy-storage units. In the present study, the temperature dependence of thermal reduction of MoO3 was surveyed at the range of 350℃ to 750℃. Upon reduction, the formed redox species characterized by EPR spectroscopy are the MoVion and superoxide anion radical (O2-) when the reduction was induced at the optimal temperature of 300-350℃. When heating-up from 350℃, the EPR signals started to decline in amplitude. The signals in the range of 400-450℃ decreased to half of that at 350℃, and then to zero at ~600℃. Further treatment at even higher temperature or prolonged heating time at 500℃ caused more reduction and more free electrons were released to the MoO3 bulk, which results in a delocalized means similar to the antiferromagnetic coupling. These data herein are helpful to prepare and study the metal-oxide catalysts.展开更多
基金supported by the National Key R&D Program of China(No.2018YFA0306600)AnHui Initiative in Quantum Information Technologies(No.AHY050000)
文摘The formation and qualification of redox sites in transition metal oxides are always the active fields related to electronics, catalysis, sensors, and energy-storage units. In the present study, the temperature dependence of thermal reduction of MoO3 was surveyed at the range of 350℃ to 750℃. Upon reduction, the formed redox species characterized by EPR spectroscopy are the MoVion and superoxide anion radical (O2-) when the reduction was induced at the optimal temperature of 300-350℃. When heating-up from 350℃, the EPR signals started to decline in amplitude. The signals in the range of 400-450℃ decreased to half of that at 350℃, and then to zero at ~600℃. Further treatment at even higher temperature or prolonged heating time at 500℃ caused more reduction and more free electrons were released to the MoO3 bulk, which results in a delocalized means similar to the antiferromagnetic coupling. These data herein are helpful to prepare and study the metal-oxide catalysts.
