PARTIAL OXIDATION OF METHANE TO SYNTHESIS GAS OVER SUPPORTED IRIDIUM CATALYSTS

Partial oxidation of methane to synthesis gas was carried out using su pported iridium catalysts. The performance of supported iridium cataly sts in synthesis gas formation depended strongly on the support materi als. Ir(5 wt%)/TiO2 afforded 25% conversion of methane (CH4/O-2=5) to give CO and H-2 With the selectivity of above 80% at 600 degrees C. Ir /TiO2 catalyst gave a CO-to-H-2 ratio of 2.0, as expected from the sto ichiometric reaction. No carbon deposition was observed with the suppo rted TiO2, and a constant activity was exhibited for at least 15 h, Th e synthesis gas yield with Ir/TiO2 catalyst was the same as supported Ph catalyst, which is reported to be the best catalyst for this reacti on. The active species of Ir/TiO2 catalyst was found to be metallic ir idium by XPS analyses. (C) 1998 Elsevier Science B.V.