Enhancing Ethanol Electrooxidation in Acidic Media Using Pt Nanoparticles Supported on Metal Oxide-Modified Vulcan XC72 Nanocomposites.

Nanocomposite electrode materials based on Pt nanoparticles (Pt NPs) deposited on various carbonaceous materials (Carbon Black-Vulcan XC72, graphene, and graphite) were fabricated and evaluated for ethanol electrooxidation reaction (EOR) in acidic media. The promotional effects of calcination and incorporation of metal oxides (TiO2, SnO2, ZnO, Fe2NiO4, Fe2O3, CuFe2O4, ZnFe2O4, and 5% Ru on alumina) into Vulcan XC-72 on the performance of Pt NPs toward EOR were systematically evaluated. Pt NPs (∼20 wt %) were synthesized via a facile NaBH4 reduction method at ambient temperature, yielding spherical nanoparticles with minimal agglomeration. Physicochemical characterization (XRD, TEM, and SEM) confirmed uniform Pt dispersion and reduced particle size on calcined Fe2O3-C supports. Electrochemical analysis (CV, CA, LSV, and EIS) revealed that calcined Pt/5% Fe2O3-C exhibited superior EOR activity, with a low onset potential (0.2 V vs Ag/AgCl), high current density (0.52 mA/cm2), and enhanced stability (retaining >34% activity after 3000 s). Dual calcination (pre/post-Pt deposition) stabilized ultrasmall Pt NPs (3.09 nm) on Fe2O3-C, achieving 2.3 times higher mass activity than Pt/C. The improved performance is attributed to synergistic electronic effects, optimized Pt-support interactions, and Fe2O3-mediated C-C bond cleavage. This work highlights the efficacy of dual thermal annealing (pre- and post-Pt deposition) in stabilizing Pt NPs and advancing DEFC catalyst design.