Experimental and computational investigation of graphite-supported Pt–Ni nanocatalyst for ethanol electro-oxidation in alkaline medium

Considering the growing demand for sustainable and environmentally friendly energy sources, the development of efficient electrocatalysts for ethanol oxidation is of significant importance. In the present study, the of Pt/Graphite (Pt/Grt) and Pt–Ni/Graphite (Pt–Ni/Grt) electrocatalysts were synthesized by a simple chemical reduction method using pristine graphite as a low-cost support and evaluated for ethanol electro-oxidation in alkaline medium. The electrocatalyst structures and morphologies were characterized using FE-SEM, TEM, EDX, and elemental mapping techniques. Their electrochemical performance toward the ethanol oxidation reaction (EOR) was investigated by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Pt–Ni/Grt showed a higher electrochemically active surface area than Pt/Grt (59 vs. 42 m 2 /g), a higher current density (0.49 vs. 0.32 mA/cm 2 ), and a lower charge-transfer resistance (1.57 vs. 3.02 Ω). In addition, the oxidation potential region shifted to more negative values for Pt–Ni/Grt, indicating more favorable ethanol oxidation behavior. The experimental investigation was complemented by quantum-mechanical (QM) calculations via density functional theory (DFT) and molecular-mechanical (MM) simulations, including Monte Carlo and molecular dynamics approaches. DFT calculations showed an increase in Pt–Ni adsorption energy on graphene from 34.38 for Pt to 84.09 kcal/mol for Pt–Ni, while the ethanol interaction energy increased from 47.73 for Pt/Gr to 114.31 kcal/mol for Pt–Ni/Gr. Overall, the experimental and computational results consistently support the superior electrocatalytic performance of the Pt–Ni/Grt toward ethanol oxidation in alkaline medium, highlighting its potential as a promising anode catalyst for direct ethanol fuel cell (DEFC) applications.