Electronic and Bifunctional Synergy in Au-Pt Nanoparticles for Highly Efficient Methanol and Formic Acid Electrooxidation in Alkaline Media

This study aims to explore the performance of hybrid electrochemical catalysts composed of platinum (Pt) nanoparticles coated with a thin layer of gold (Au) for the oxidation of both methanol (MOR) and formic acid (FAOR) in an alkaline electrolyte (KOH). Cyclic voltammetry (CV) and Chronoamperometry (CA) analyses confirmed the formation of a well-defined Au-core/Pt-shell structure with clear electronic interaction, evidenced by a positive shift in Pt ۴f binding energy. Electrochemical evaluation conducted using ۰.۵ M KOH indicated that for the oxidation of methanol and formic acid, Au-Pt had approximately ۲.۱ and ۱.۸ times greater mass activity, respectively, than Pt alone. The negative shift in the onset potential was between ۴۵ and ۶۰ mV, and the stability of the chronoamperometric response was increased by over ۲.۵ times. This increase was attributed to the presence of some factors, such as bifunctional synergy, ligand effects, and strain. The Au-Pt combination indicated significantly higher current densities than pure Pt and a lower initial oxidation potential than pure Pt, as well as greater tolerance for impurities through intermediate oxidation. Thus, the presence of this type of alkaline solution allows for a more effective reaction process and minimizes corrosion problems with the hybrid catalyst, indicating its potential for sustainable energy applications.

کلیدواژه ها:

Methanol oxidation ، Formic acid oxidation ، Pt nanoparticles ، Hybrid catalysts ، Alkaline medium ، Fuel cells