Operando characterisation of alumina-supported bimetallic Pd-Pt catalysts during methane oxidation in dry and wet conditions

Near ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) was used to study the chemical states of a range of alumina-supported monometallic Pd and bimetallic Pd-Pt nanocatalysts, under methane oxidation conditions. It has been suggested before that for optimal complete methane oxidation, palladium needs to be in an oxidised state. These experiments, combining NAP-XPS with a broad range of characterisation techniques, demonstrate a clear link between Pt presence, Pd oxidation, and catalyst activity under stoichiometric reaction conditions. Under oxygen-rich conditions this behaviour is less clear, as all of the palladium tends to be oxidised, but there are still benefits to the addition of Pt in place of Pd for complete oxidation of methane.

Automated summary

Near ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) was used to study the chemical states of alumina-supported monometallic Pd and bimetallic Pd-Pt nanocatalysts under methane oxidation conditions. The presence of Pt was found to be linked to Pd oxidation and catalyst activity under stoichiometric reaction conditions, while under oxygen-rich conditions, the behavior was less clear. However, adding Pt in place of Pd still showed benefits for complete oxidation of methane.