Pulsed laser-driven green synthesis of trimetallic AuPtCu nanoalloys for formic acid electro-oxidation in acidic environment

Abstract

The process of hydrogen energy storage via water electrolysis is challenging because of the highly explosive nature of hydrogen gas. To circumvent this issue, the formic acid aqueous solution is being intensively investigated in the field of fuel cells as of its excellent stability and no hazard of combustion or explosion. In formic acid oxidation (FAO), a formic acid solution is decomposed into CO2, thus generating hydrogen ions and electrons. This process can occur via two pathways, i.e., with or without CO generation. In this study, we prepared AuPtCu alloys as a catalyst for formic acid fuel cell (FAFC) usage employing an ecofriendly pulsed laser without requiring a reducing agent or surfactant. The FAO process catalyzed by the AuPtCu alloys was found to ensue via a direct path, i.e., dehydrogenation in the existence of Pt and Au. Formic acid was directly oxidized to CO2 while CO was removed by Cu. The optimal Au1Pt1Cu0.5 catalyst exhibited the best electrochemical FAO activity, outperforming traditional Pt/C, most likely because of the Cu content enhancing the amount of active surface sites. This research demonstrates the potential of AuPtCu for application in direct FAFCs as a power source for transportable devices.