Segmented Au/PtCo heterojunction nanowires for efficient formic acid oxidation catalysis

Exploring a new strategy for the removal of adsorbed CO (CO*) on a Pt surface at a low potential is the key to achieving enhanced catalysis for the formic acid oxidation reaction (FAOR); however, the development of such a strategy remains a significant challenge. Herein, we report a class of Au/PtCo heterojunction nanowires (HNWs) as efficient electrocatalysts for accelerating the FAOR. This heterojunction structure and the induced Co alloying effects can facilitate formic acid adsorption/activation on Pt with high CO tolerance, generating the FAOR pathway from dehydration to dehydrogenation. The optimized Au23/Pt63Co14HNWs showed the highest specific and mass activities of 11.7 mA cm−2Ptand 6.42 A mg−1Ptreported to date, respectively, which are considerably higher than those of commercial Pt/C. DFT calculations confirmed that the electron-rich Au segment enhances the electronic activity of the PtCo NWs, which not only allows the construction of a highly efficient electron transfer channel for the FAOR but also suppresses CO formation.