Coni Alloy Nanoparticles Encapsulated In N-Doped Graphite Carbon Nanotubes As An Efficient Electrocatalyst For Oxygen Reduction Reaction In An Alkaline Medium

Transition metal alloys and their compounds have been drafted as relatively economic and high-activity non-noble metal electrocatalysts for the oxygen reduction reaction (ORR). However, the stability of catalysts is regarded as a critical issue for practical application. Here, we report CoNi alloy nanoparticles embedded in a nitrogen-doped graphite carbon nanotube (CoNi@N-GCNT-FD) electrocatalyst, which is synthesized from metal precursors and dicyandiamide nanofibers formed by freeze-drying pretreatment. The electrocatalyst exhibits remarkable ORR performance (a positive onset potential at 0.90 V vs reversible hydrogen electrode (RHE), a half-wave potential at 0.84 V vs RHE, and a high limiting current density (6.4 mA cm(-2))) in an alkaline medium. The outstanding ORR catalytic behavior is attributable to the properties with a high specific surface area and the collaborative influence between a CoNi alloy and a nanotube protective layer. The CoNi@N-GCNT-FD also displays antimethanol toxicity and good stability over 10,000 cycles, attributed to the unique structure of N-GCNT that is more conducive to mass transfer and protects the alloy particles from corrosion under harsh conditions. This simple route can be widely used to prepare other alloy electrocatalysts with relatively economic value and high performance in power conversion and stockpile device fields.