Honeycomb supported Co3O4/CeO2 catalyst for CO/CH4 emissions abatement:: Effect of low Pd-Pt content on the catalytic activity

A structured Co3O4-CeO2 composite oxide, containing 30% by weight of Co3O4, has been prepared over a cordieritic honeycomb support. The bimetallic, Pd-Pt catalyst has been obtained by impregnation of the supported Co3O4-CeO2 with Pd and Pt precursors in order to obtain a total metal loading of 50 g/ft(3). CO, CH4 combined oxidation tests were performed over the catalyzed monoliths in realistic conditions, namely GHSV = 100,000 h(-1) and reaction feed close to emission from bi-fuel vehicles. The Pd-Pt un-promoted Co3O4-CeO2 is promising for cold-start application, showing massive CO conversion below 100 degrees C, in lean condition. A strong enhancement of the CH4 oxidation activity, between 400 and 600 degrees C, has been observed by addition to the Co3O4-CeO2 of a low amount of Pd-Pt metals. (c) 2006 Elsevier B.V. All rights reserved.