Combustion of methane at low temperature over Pd and Pt catalysts supported on Al2O3, SnO2 and Al2O3-grafted SnO2

Pd and Pt catalysts supported on alumina, tin(IV) oxide and tin(IV) oxide g rafted on alumina were prepared, characterised and tested with respect to t he low-temperature combustion of methane after reduction in H-2 and ageing under reactants at 600 degreesC. In the case of Pd, the use of SnO2 or SnO2 -based supports led to catalysts slightly less active than Pd/Al2O3. In con trast, SnO2 was found to strongly promote the oxidation of methane over Pt catalysts with respect to Pt/Al2O3, even after ageing under reactants. When Pt was supported on SnO2 grafted on Al2O3, the activity was found at most similar to or, after ageing, lower than Pt/Al2O3. This negative effect was discussed, being partly related to the sintering of SnO2 under reactants ob served by FTIR and XRD.