Selective oxidation of carbon to carbon monoxide over reduced CeO_2/Fe_2O_3 catalysts

摘要

CeO_2/Fe_2O_3 mixed oxides were prepared by the co-precipitation method. Materials containing carbon were obtained by the step of CeO_2/Fe_2O_3 compound reaction with methane for 60 min. Raman spectra and TEM were used to study the structure of formed carbon. The carbon oxidations over cerium iron catalysts in the absence or presence of a gaseous oxidant were investigated. The Raman results showed that the carbon species exist in the form of high graphitization carbon nanotubes. The continuous reactions indicated that the oxidation of carbon on the surface of cerium iron catalyst by air caused complete removal of carbon as carbon monoxide with high selectivity (>90%) at 800°C,and the solid-solid reaction between carbon and CeO_2/Fe_2O_3 mixed oxides should play a significant role to promote the formation of CO in this process. In conclusion, it is confirmed that the selective transformation of carbonaceous species from methane decomposition to valuable CO is possible.