Bimetallic nanocatalysts supported on sugarcane leaf-derived carbon for enhanced performance in direct alcohol fuel cells

Abstract

This study explores the potential of sugarcane leaf-derived activated carbon (SLAC) as a novel support material for PtSnO₂ electrocatalysts in direct ethanol fuel cell (DEFC). SLAC was synthesized via hydrothermal carbonization and activation processes to meet specific structural and surface requirements. Electrocatalysts were prepared using the polyol method and characterized through XRD, TEM, and XPS to analyze their physical and chemical properties. The investigation focused on the impact of carbon support impurities and the role of nitrogen doping on the electrochemical performance of ethanol oxidation reaction (EOR). The findings revealed that impurities in carbon support hindered performance by increasing onset potential and reducing current density due to blockage of the porous structure and disrupted electrostatic interactions between the bimetallic catalyst and the support. In contrast, N-doped SLAC improved performance by providing uniform metal dispersion, resulting in enhanced electron-rich sites. PtSnO₂/N-doped SLAC exhibited superior performance, achieving the lowest onset potential, highest current density, and enhanced mass activity during EOR testing. This improvement is attributed to the synergistic effect of N-doped SLAC and SnO₂, which provided electron-rich sites and improved CO tolerance through oxygen species that removed CO adsorption on the Pt surface. In DEFC testing, PtSnO₂/N-doped SLAC demonstrated the highest performance, with an open circuit voltage (OCV) of 0.791 V, a peak current density of 350 mA/cm², and a maximum power density of 65.07 mW/cm². This work highlights the novel application of SLAC as a sustainable, high-performance support material for DEFC, offering insights into addressing impurity challenges and advancing clean energy technologies.