Dealloying monolithic Pt-Cu alloy to wire-like nanoporous structure for electrocatalysis and electrochemical sensing

Micrometer wire-like PtCu catalysts with nanoporous structure and tunable composition were fabricated by dealloying Pt₃Cu₉₇. When the Pt:Cu ratio is lower than 1:99, dealloying results in dispersed PtCu nanoporous nanoparticles and/or single nanoparticles. Material characterization by X-ray diffraction and electron microscope shows that the formation of wire-like morphology is due to the large-scale shrink of the long rod-like alloy grains during the dealloying. The composition of the dealloyed nanoporous PtCu can be widely tuned by changing the concentration of the dealloying solution. Electrochemical test shows that the wire-like porous PtCu alloys show enhanced and composition-dependent catalytic activity for H₂O₂ electro-reduction.