Construction of PtAg-on-Au Heterostructured Nanoplates for Improved Electrocatalytic Activity of Formic Acid Oxidation

Direct formic acid fuel cells have attracted significant attention due to their low fuel crossover, high safety, and high theoretical power density among all proton-exchange membrane fuel cells. Numerous efforts have been dedicated to studying formic acid oxidation, particularly in the fabrication of high-performance electrocatalysts with economical utilization of Pt metal. In this work, we report a synthetic strategy to create PtAg dots supported on plate-like Au nanoparticles and explore their applications in electrocatalytic formic acid oxidation. The highly dispersed nature of the catalytic Pt centers and the successful construction of PtAg−Au trimetallic interfaces makes the current nanostructure an ideal system to allow for a synergetic effect between Pt, Au, and Ag, leading to improved electrocatalysis. Compared with commercial Pt/C, our PtAg-on-Au heterogenous nanoplates exhibit superior mass activity, along with enhanced reaction kinetics and long-term durability for FAOR in an acidic medium. Density functional theory (DFT) simulation results indicate that AgPtAu(111) exhibits a relatively high activity for HCOOH oxidation into CO₂ among the various Au-based catalysts. This work provides a viable strategy for constructing Pt-based electrocatalysts with controlled Pt ensembles, offering insights into the development of fuel cell catalysts that make highly efficient use of costly noble metals.