REFORMING OF METHANE OVER CIRIA AND PEROVSKITE-BASED CATALYSTS Subtitle

The influence of the nature of the support on the activity of rhodium-based catalysts in the catalytic reforming of methane has been studied. Based on the variety of applications of methane reforming a selection of supports was made including fluorites, perovskites and aluminum oxide. In the absence of rhodium, the perovskite and fluorite supports, i.e. SrFe0.67Co0.33O3+•, La0.6Sr0.4Co0.2Fe0.8O3+•, Ce0.8Gd0.2O1.9+•, and CeO2-ZrO2 all showed activity for the total combustion of methane but proved to be poor reforming catalysts. Impregnation of the fluorite and alumina supports with rhodium provided active catalysts for the reforming of methane. The activity of perovskite-supported rhodium appeared to depend strongly on the reducibility of the perovskite. Rhodium supported on La0.77Sr0.13MnO3+ • is a reasonably active catalyst, but it deactivates rapidly. Rhodium supported on mixed valence oxides SrFe0.67Co0.33O3+ • or La0.6Sr0.4Co0.2Fe0.8O3+ • is hardly more active than the bare support. Application of other metals active in reforming such as platinum, ruthenium, nickel, or palladium on La0.6Sr0.4Co0.2Fe0.8O3+ • lead to surprisingly low catalytic activity. For supported rhodium catalysts a relation is suggested between reducibility of the support materials and catalytic activity for the reforming of methane, which is presently under further investigation