The catalytic partial oxidation of methane has been studied over platinum silicon nitride supported catalysts in the temperature range of 900-1 100 degreesC at a contact time of 0.35 ms at atmospheric pressures. The feed consisted of a mixture of CH4/O-2/N-2 approximate to 2/1/10. The catalysts were prepared by impregnation of platinum bis-acetyl-acetonate on silicon nitride powder (Si3N4). The different catalysts were characterized by chemical analysis, XPS and TEM. Minor particle sintering occurs during reaction. Metal losses were observed at 900 degreesC, for catalysts containing 1.0 and 2.2 wt% of platinum. A catalyst with a low amount of platinum (0.045 wt.%) appeared to be stable at 900 degreesC, as no platinum loss was observed. The high stability of the 0.045 wt% Pt/Si3N4 catalyst could be attributed to particular interactions between the metal and the support. (C) 2001 Elsevier Science B.V. All rights reserved.