Layered double hydroxides-derived CoNi alloy nanoparticles encapsulated by porous N-doped carbon nanofibers as efficient methanol electrocatalysts for alkaline direct methanol fuel cells

Abstract

The exploration of inexpensive electrocatalysts possessing high activity and increased stability to replace precious metal catalysts in the methanol oxidation reaction (MOR) is highly desirable for alkaline direct methanol fuel cells (ADMFCs). This study presents a novel approach to synthesize layered double hydroxides (LDHs)-derived CoNi alloy nanoparticles confined within porous N-doped carbon nanofibers (CoNi@NCNFs) via facile electrospinning and pyrolysis for methanol electrooxidation. The one-dimensional N-doped carbon nanofibers could effectively prevent nanoparticle agglomeration during the pyrolysis of LDH precursors. The optimized CoNi@NCNF3–900 composite exhibits exceptional catalytic activity (80.3 mA cm⁻²) for MOR in alkaline solution, attributed to its hierarchical porous structure, high surface area, and abundant accessible active sites. Furthermore, the catalyst demonstrates competitive electrocatalytic stability, retaining over 90 % of its initial current density after 1000 consecutive cyclic voltammetry (CV) cycles. Notably, a single-cell ADMFC assembled with CoNi@NCNF3–900 as the anode catalyst achieves a promising maximum power density of 29.5 mW cm⁻², highlighting the potential of CoNi@NCNF3–900 for application in DMFC technology and clean energy sources.