Toward new Pt- and Rh-based catalysts for methane partial oxidation at high temperatures and short contact times

At high temperatures, using conventional supports (SiO2, Al2O3) usually an important deactivation is observed due to particle sintering. In this study , ae have prepared 1.0 wt. % Pt and Rh 0.5 wt. % catalysts supported on a n ew Si3N4 ceramic by using impregnation with Pt(C5H7O2)(2) and Rh(NO3)(2). T he catalytic performances were evaluated between 900 and 1100 degreesC at c ontact times between 0.35 and 6.90 ms at atmospheric pressure, The feed was a CH4/O-2/N-2 approximate to 2/1/10 mixture. These materials were found to present an exceptional thermal stability with a minor particle sintering. Metal loss was observed only for the platinum catalyst. (C) 2000 Academie d es sciences / Editions scientifiques et medicales Elsevier SAS (C) 2000 Aca demie des sciences / Editions scientifiques et medicales Elsevier SAS.