Pd/fMC−NiO Synergistic, Promotional Effect and Cooperation Induced Electrocatalysis towards Ethylene Glycol Electrooxidation: Experimental Approach and DFT Calculations

Abstract

Direct alcohol fuel cells (DAFCs) face several challenges such as carbon support corrosion, poor kinetics, and long-term stability, requiring improved electrocatalyst support development. We synthesized 5 %Pd/fMC−NiO using a microwave-assisted sodium borohydride-enhanced polyol method. X-ray photoelectron spectroscopy, transmission electron microscope, and X-ray diffractometry probed the material's surface composition, morphology, and structure. ICP-OES is employed to quantify palladium loading. Fourier Transform Infrared Spectroscopy mapped the functional groups. Cyclic voltammetry, linear sweep voltammetry, electrochemical impedance spectroscopy, and chronoamperometry show that the 5 %Pd/fMC−NiO has the lowest activation energy, and with that, the best electroactivity, which is ~16 times higher compared to commercial Pd/C; additionally, the catalyst shows anti-poisoning properties, and long-term durability. This is merited to the cooperation and promotional effect of Pd/fMC−NiO. The electrocatalysts’ electroactivity improved via enhanced electron movement instigated by NiO. This study introduced the parallelism effect concept borrowed from the graphite structure for controlled electron channeling the 5 % Pd/fMC−NiO electrocatalyst. The theoretical calculations corroborated the experimental findings that our approach favors anchoring and dispersing Pd NPs uniformly, demonstrating NiO′s cooperative and promotional effects. Thus, opening new opportunities for the development of electrocatalysts for high-performance DAFCs.