In Situ XRD and In Situ IR Spectroscopic Analyses of Structural Change of Goethite in Methane Oxidation

This paper examines the methane oxidation activity of iron oxides from goethite synthesized from different types of iron compounds. The variation of crystal structure caused by heat treatment of goethite under methane and oxygen gas mixtures was investigated by in situ X-ray diffractometry and in situ infrared spectroscopy. Methane oxidation commenced at a low temperature of 573 K when goethite was used as a catalyst, after the goethite had changed into hematite by dehydration at approximately 493 K. It was found that the active species in methane oxidation was hematite.