Reverse Micelle Synthesis of AuyNi100-y Nanoparticles Decorated Multiwalled Carbon Nanotubes as High-Performance Anode Electrocatalysts for Direct Borohydride-Hydrogen Peroxide Fuel Cells

Abstract

Cost-effective and efficient electrocatalysts for the borohydride oxidation reaction (BOR) are essential for improving the performance of direct borohydride-hydrogen peroxide fuel cells (DBHPFCs). In this work, AuNi nanoparticles decorated multiwalled carbon nanotubes (MWCNT) (AuNi/MWCNT) were synthesized via a reverse micelle method using sodium bis(2-ethylhexyl) sulfosuccinate at 303 K and applied as anode electrocatalysts for DBHPFCs. Various physicochemical and electrochemical characterization techniques were employed. Among the synthesized catalysts, Au₅₀Ni₅₀/MWCNT demonstrated superior performance, including a higher electrochemically active surface area (ECSA: 923 cm² mg⁻¹), turnover frequency (TOF: 0.21 s⁻¹), peak current density (73 mA cm⁻²), lower activation energy (7.4 kJ mol⁻¹), exchanged electron number (5.8), lower charge transfer resistance (47.66 ohms), highest stability, and the lowest poisoning rate (0.14 $$ 10⁻³% s⁻¹) compared to Au₁₀₀/MWCNT and others. DBHPFCs constructed with Au₅₀Ni₅₀/MWCNT as the anode and a Pt mesh (1 cm × 1 cm) as the cathode achieved a peak power density of 67.11 mW cm⁻² and a current density of 70 mA cm⁻² at 303 K. The exceptional electrocatalytic performance of the AuNi/MWCNT electrocatalyst offers valuable insights for developing innovative, cost-effective, and durable electrocatalysts for DBHPFC applications.