Insight into mechanism of iron-oxides reduction in atmospheres of CH4 and CO

Abstract

First-principle calculations are carried out to interpret the experimental observations and to generate the mechanisms of CO and CH4 conversion with Fe2O1-3. The stabilization of FeC bonding involves π∗(CO) and electron donating from oxygens’ LP. The FeO bond activation is rate-limiting step of conversions. Stabilization and activation are affected by number of oxygens at the iron active site. Low ORBs are identified for CO + Fe2O1-3 reaction pathways. Significant ORBs are calculated for Fe2O3 + CH4, and the competing mechanism of reduction by H2 is shown. DFT calculations suggest favorable formation of Fe3C in atmosphere of CH4 and its oxidation in atmosphere of CO.