The oxidation of formic acid at noble metal electrodes Part 4. Platinum + palladium alloys

Formic acid oxidation has been studied on Pt + Pd alloys of known surface composition using cyclic voltammetry. The results are interpreted in terms of a strongly bound (poisoning) intermediate which adsorbs only on the Pt atoms and a direct oxidation path which involves an intermediate occupying a single site and a second intermediate occupying two sites. Steady state oxidation currents on the alloys at potentials in the range of about 0.4 to 0.9 V are larger than expected from a linear combination of the currents on the pure metals. This effect may be due to the modification of metal properties at the junction between two types of metallic atoms.