Speaker
Description
Currently, Pt nanoparticles-supported carbon materials serve as cathode electrocatalysts for the oxygen reduction reaction (ORR) in commercial hydrogen fuel cells. However, Pt has a high cost, scarcity, and low durability. To address these challenges, nitrogen-doped carbons (NC) have been explored as potential ORR electrocatalysts due to their cost-effectiveness and high durability. Recently, integrating NC with 1D or 2D materials has emerged as a promising strategy to significantly enhance ORR activity and durability. In this study, NCs synthesized from 2-cyanopyridine via the solution plasma process were integrated with various 1D carbon materials, including multi-walled carbon nanotube (MWCNT), single-walled carbon nanotube (SWCNT), cup-stacked carbon nanotube (CSCNT), and carbon fiber (CF). Subsequently, the composites were annealed at 900°C under the Ar atmosphere. The X-ray diffraction (XRD) analysis revealed the amorphous carbon of NCs and the graphitic structure of the 1D carbons. Field-emission electron microscopy (FE-SEM) displayed nanosized carbon particles attached on the rod-like structure of 1D carbons. The ORR activity was evaluated in O2/N2-statured 0.1 M KOH electrolyte using a three-electrode system via cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The results showed that the 1D/NC composites exhibited enhanced ORR activity in terms of both onset potential and current density compared to the NC catalyst. The electron transfer number of the 1D/NC composites, calculated from the rotating-ring disk electrode (RRDE), was found to be 3.5–3.7, indicating the dominant 4-electron reduction path-way. The enhanced ORR activity can be attributed to two possible reasons: (i) enhanced electron transport facilitated by the high conductive partway of 1D carbons and (ii) increased active sites resulting from the prevention of NC particle agglomeration.
