Carbon supported Pd–Cu nanoalloys: support and valence band structure influence on reduction and oxidation reactions

The present study has tracked the changes on the electronic and structural properties of Pd-Cu nanoalloys that were influenced by composition and the chosen support. Carbon supported Pd-Cu nanoalloys (PdxCu1-x/C for x = 1, 0.7, 0.5, 0.3 and 0) were submitted to sequential thermal treatments (up to 450°C) to induce reduction and oxidation reactions. Valence band photoemission data and in situ XAS results showed that stronger oxygen-metal bonds are formed in the Cu-richer samples. A regeneration process assisted by the support was observed during the oxidation reaction, and its reduction efficiency was found to be dependent on the distribution of occupied electronic states near the Fermi level.