Ultrafine nanoporous PdFe/Fe3O4 catalysts with doubly enhanced activities towards electro-oxidation of methanol and ethanol in alkaline media

Here, we report the fabrication of ultrafine nanoporous PdFe/Fe3O4 electrocatalysts by a facile dealloying strategy. The results show that the phase formation of the as-dealloyed samples is dependent upon the Pd : Fe atomic ratio in the Al–Pd–Fe ternary precursors. The size of ligaments is as small as ∼2 nm in the nanoporous structure of the as-dealloyed samples, which is the smallest among the literature data reported for nanoporous metals/alloys. The present nanoporous PdFe/Fe3O4 nanocomposites show excellent electrocatalytic activities towards the oxidation of methanol and ethanol in alkaline media due to the double enhancement from Fe3O4 and Fe in PdFe. In addition, the nanoporous PdFe/Fe3O4 sample dealloyed from the Al75Pd12.5Fe12.5 precursor exhibits the highest electrocatalytic activity. These materials are potential anode electrocatalysts for applications in direct alcohol fuel cells.