In situ Studies of Alloy Formation on a Pd/Ga2O3 Methanol Steam Reforming Catalyst

Methanol steam reforming is a promising reaction in terms of hydrogen production for use in PEM fuel cells. Catalyst research has focused mainly on Cu/ZnO formulations, because of their superior selectivity to CO2 and H2. The common byproduct CO is problematic due to its poisoning effect on the anode of a downstream fuel cell. Some years ago it was shown that palladium supported on certain reducible oxides (ZnO, Ga2O3, In2O3) matches the copper based catalysts in selectivity while providing a higher thermal stability [1]. As a reason for the improved selectivity the formation of an alloy or intermetallic compound (IMC) between Pd and the reduced support has been suggested. The aim of this work was the investigation of alloy formation on a 5 wt% Pd/Ga2O3 powder catalyst under reducing conditions. The bulk information obtained by in situ XRD was complemented by the surface sensitive information from IR spectroscopy and in situ XPS.