Catalytic conversion of methane to synthesis gas over europium iridate, Eu2Ir2O7: Anin situ study by x-ray diffraction and mass spectrometry

Abstract

The selective partial oxidation of methane over the europium iridium pyrochlore, Eu2Ir2O7, has been studiedin situ by using powder X-ray diffraction and mass spectrometry. At a temperature of 873 K and 1 atmosphere pressure, with a CH4∶O2 ratio of 2∶1 under argon dilution, high yields of synthesis gas are obtained. The pyrochlore structure of the iridate is modified during the initiation of the catalyst, giving an active solid that is shown to comprise particles of iridium metal, ∼ 30 A in diameter, supported on europium oxide, Eu2O3. The modification of the pyrochlore structure was monitored by X-ray diffraction, and the product gases were continuously analysed by mass spectrometry.