A displacement dealloying route to dilute nanoporous PtAu alloys for highly active formic acid electro-oxidation

Highlights: • A facile displacement dealloying strategy for nanoporous alloy fabrication is reported. • Dilute nanoporous PtAu alloys contain highly dispersed Pt atoms and atomic clusters. • Nanoporous PtAu alloys demonstrate enhanced dehydrogenation path selectivity with remarkable catalytic activity for formic acid electro-oxidation. -- Abstract: Functional nanoporous metals and alloys can be fabricated by chemical or electrochemical dealloying routes in corrosive media, followed by customized surface functionalization. The present work describes how a combination of displacement reaction and dealloying can provide a facile one-pot procedure to nanoporous alloys such as PtAu, and the resulted electrocatalysts are characterized by highly dispersed Pt atoms or small clusters embedded within a high surface area Au matrix. These dilute alloy electrocatalysts with low Pt contents exhibit remarkable activity toward formic acid oxidation via a favorable dehydrogenation mechanism. At 0.6 V versus reversible hydrogen electrode, they can demonstrate over 70-fold enhancement in Pt mass activity than that of the commercial Pt/C.