Theoretical and Experimental Exploration of Au-Pt Anode for Efficient Ascorbate Oxidation in Sustainable Fuel Cells

The development of efficient and non-toxic fuels for direct liquid fuel cells has highlighted ascorbic acid (AA) as a sustainable energy source. This study presents a combined theoretical and experimental investigation of ascorbate oxidation on an Au-Pt electrode in alkaline medium. Density functional theory (DFT) calculations reveal that Au deposition on Pt creates a more homogeneous and active surface, significantly enhancing the adsorption energy of ascorbate (−7.54 eV vs. −5.80 eV on bare Pt). Electrochemically, this translates to a superior performance, where the Au-Pt electrode achieves a 38% reduction in charge-transfer resistance, a higher current density, and a lower Tafel slope of 77 mV dec−1, indicating accelerated kinetics. The electrode also retains its activity over 1000 cycles, confirming exceptional durability. This synergistic combination of theoretical and experimental results establishes Au-Pt as a premier catalyst for sustainable ascorbate-based energy conversion.