Ultrafine nanoporous PdFe/Fe3O4catalysts with doubly enhanced activities towards electro-oxidation of methanol and ethanol in alkaline media

Abstract

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 Al₇₅Pd_12.5Fe_12.5 precursor exhibits the highest electrocatalytic activity. These materials are potential anode electrocatalysts for applications in direct alcohol fuel cells.