Silicon nitride supported platinum catalysts for the partial oxidation of methane at high temperatures

The catalytic partial oxidation of methane has been studied over platinum s ilicon nitride supported catalysts in the temperature range of 900-1 100 de greesC at a contact time of 0.35 ms at atmospheric pressures. The feed cons isted 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 nitri de powder (Si3N4). The different catalysts were characterized by chemical a nalysis, XPS and TEM. Minor particle sintering occurs during reaction. Meta l 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.%) ap peared 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 pa rticular interactions between the metal and the support. (C) 2001 Elsevier Science B.V. All rights reserved.