DECOMPOSITION OF CO2 AND CO INTO CARBON WITH ACTIVE WUSTITE PREPARED FROM ZN(II)-BEARING FERRITE

CO2 decomposition reaction into carbon was studied at 300-degrees-C using the H-2-reduced Zn(II)-bearing ferrite which consisted of the Zn(II) oxide and the active wustite. The H-2-reduced Zn(Il)-bearing ferrite was prepared from Zn(II)-bearing ferrite by the reduction with H-2 gas at 300-degrees-C. The wustite (Fe(delta)O) in the H-2-reduced Zn(II)-bearing ferrite had a higher delta value (delta = 0.97, active wustite) than those of the normal wustites (0.90 < delta < 0.95) prepared at high temperatures ( > 570-degrees-C). The decomposition reaction of CO2 proceeds in two steps: (1 ) CO2 reduction to CO, and (2) CO decomposition into carbon. In the initial stage, the reduction of CO2 into CO takes place, accompanying both the oxidation of the active wustite to the slightly oxidized wustite, and the transformation of active wustite and Zn(II) oxide into the Zn(II)-bearing ferrite. After the reaction of the initial stage attains equilibrium of an apparent state of rest, the adsorbed CO is decomposed into carbon, associated with the transformation of the slightly oxidized wustite and the Zn (II) oxide into the Zn (II)-bearing ferrite.