CO2 Decomposition with Nano-Size Ferrite Prepared by Irradiation of Ultrasonic Wave

概要

論文の詳細を見る
In order to improve the reactivity of the redox reaction for the CO2 decomposition, the nano-size ferrite (Ni0.5Cu0.5)Fe2O4 with spinel structure was prepared by the irradiation of the ultrasonic wave for 6 h. The particle size of the prepared ferrite was smaller than 20 nm and it was applied to the CO2 decomposition reaction. The reduction of the ferrite using 5% H2 in Ar gas started from 180°C and its weight decreased about 24 wt% up to 800°C. After the reduction, the single phase of (Ni0.5Cu0.5)Fe2O4 changed to mixed phases of Fe, Cu, Fe-Ni, and FeO. The CO2 decomposition with the reduced ferrite up to 800°C consisted of the two-step reaction. In the first step, the weight of the reduced ferrite increased slowly, and CO was produced as a main product. In the second step, however, the weight of the reduced ferrite increased rapidly, and carbon was produced at the same time as producing CO. After the CO2 decomposition, the weight of the reduced ferrite increased about 15 wt% and its phase changed to a mixed phase of metallic Ni and Cu, and Fe3O4. So, CO2 was decomposed by oxidation of Fe and FeO. When Fe was oxidized by CO2, in the first CO2 decomposition CO was produced by a catalytic action of Cu, but in the second CO2 decomposition, carbon and CO were produced by a catalytic action of Ni with Cu.
公益社団法人日本セラミックス協会の論文