Alcohol electrooxidation on three-component NiO/La2O3/MWCNTs catalyst for DAFC application

Abstract

Alcohol electrooxidation is a crucial reaction in direct alcohol fuel cells (DAFCs), efficiently converting alcohols like methanol and ethanol into electricity with minimal environmental impact, offering a sustainable alternative to fossil fuels. This process is vital for renewable energy technologies, promoting clean energy solutions. Research in this field considers electrocatalyst development, improving reaction kinetics, and reducing fuel cell costs. The wide application of catalyst-based metal oxides led us to synthesize a three-component catalyst, including nickel oxide (NiO)/lanthanum oxide (La₂O₃) catalyst and its hybrid with carbon nanotubes (MWCNT), with the hydrothermal method. The capability of catalysts was investigated in alcohol oxidation reactions (AOR). The successful synthesis of NiO/La₂O₃ and NiO/La₂O₃/MWCNTs catalysts was confirmed. The effect of adding carbon nanotubes to the NiO/La₂O₃ double metal oxide structure on the methanol and ethanol oxidation reaction (MOR and EOR) was investigated. In MOR and EOR by NiO/La₂O₃/MWCNTs catalyst, the maximum current densities of 110.71 and 43.56 mA/cm² were obtained at potentials of 0.66 and 0.62 V, respectively, representing relatively good efficiency as a direct alcohol fuel cell (DAFC) catalyst. Also, the comparison of the Tofel slope of NiO/ La₂O₃ and NiO/La₂O₃/MWCNTs catalysts in MOR and EOR processes shows the faster kinetics of the catalyst containing carbon nanotubes in these processes. So, good performance and high stability of catalysts can be promising for further operational investigations.