Enhanced Electrocatalytic Performance of Nickel-Cobalt-Titanium Dioxide-Embedded Carbon Nanofibers for Direct Alcohol Fuel Cells

Abstract

This study focuses on making non-precious electrocatalysts for improving the performance of Direct Alcohol Fuel Cells (DAFCs). Specifically, it examines the oxidation of ethanol and methanol. Conventional platinum-based catalysts are expensive and suffer from problems such as degradation and poisoning. To overcome these challenges, we fabricated tri-metallic catalysts composed of nickel, cobalt, and titanium dioxide (TiO2) embedded in carbon nanofibers (CNFs). The synthesis included electrospinning and subsequent carbonization as well as optimization of parameters to achieve uniform nanofiber morphology and high surface area. Electrochemical characterization revealed that the incorporation of TiO2 significantly improved electrocatalytic activity for ethanol and methanol oxidation, with current densities increasing from 57.8 mA/cm2 to 74.2 mA/cm2 for ethanol and from 38.69 mA/cm2 to 60.39 mA/cm2 for methanol as the TiO2 content increased. The catalysts showed excellent stability, with the TiO2-enriched sample (T2) showing superior performance during longer cycling tests. Chronoamperometry and electrochemical impedance spectroscopy are used to examine the stability of the catalysts and the dynamics of the charge carriers. Impedance spectroscopy indicated reduced charge transfer resistance, confirming enhanced activities. These findings suggest that the synthesized non-precious electrocatalysts can serve as effective alternatives to platinum-based materials, offering a promising pathway for the development of cost-efficient and durable fuel cells. Research highlights non-precious metal catalysts for sustainable fuel cell technologies.