Deep oxidation of methane on particles derived from YSZ-supported Pd-Pt-(O) coatings synthesized by Pulsed Filtered Cathodic Arc
Résumé
Methane total oxidation was studied between 250 and 800 degrees C in a specific quartz reactor for Pd, PdOy, Pd0.6Pt0.4Oy and Pd0.4Pt0.6Oy thin films deposited on yttria stabilized zirconia (YSZ) substrates. Pt containing. films exhibited poor activity and a rapid thermal decomposition. Pd and PdOy films showed good activity and transformed to particles dispersed on the YSZ substrates. The higher reaction rate of PdOy films was explained by a better dispersion of the catalyst. A drop of the reaction rate was observed when the temperature exceeded 735 degrees C and 725 degrees C for initially Pd and PdOy, respectively, which can be associated with the decomposition of PdO into Pd and O-2. The good cycling stability and catalytic efficiency of the latter films render it promising for the pollution control in methane combustion. (C) 2009 Elsevier B.V. All rights reserved.