Item

Abstract

The development of low-temperature fuel cells for clean energy production is an appealing alternative to fossil-fuel technologies. CO is a key intermediate in the electro-oxidation of energy carrying fuels and, due to its strong interaction with state-of-the-art Pt electrodes, it is known to act as a poison. Here we demonstrate the ability of Earth-abundant Cu to electro-oxidize CO effi-ciently in alkaline media, reaching high current densities of ≥0.35 mA cm⁻² on single-crystal Cu(111) model catalysts. Strong and continuous surface structural changes are observed under reaction conditions. Supported by first-principles microkinetic modelling, we show that the concomitant presence of high-energy undercoordinated Cu structures at the surface is a prereq-uisite for the high activity. Similar CO-induced self-activation has been reported for gas–surface reactions at coinage metals, demonstrating the strong parallels between heterogeneous thermal catalysis and heterogeneous electrocatalysis.