Unveiling the potential of ultra-low load Co on porous carbon-rich SiCN(O) fibre mats towards oxygen electrocatalysis in alkaline medium
Résumé
The development of efficient and cost-effective catalysts for the oxygen electrocatalysis is crucial for advancing renewable energy technologies, such as fuel cells, electrolyzers and metal-air batteries. Herein, we report the high efficiency of Co nanoclusters generated on porous silicon oxycarbonitride (SiCN(O)) fibre mats towards Oxygen Reduction Reaction (ORR) and Oxygen Evolution Reaction (OER) in alkaline medium. Porous SiCN(O) ceramic fibrous supports were synthesized via electrospinning of a blend of oligosilazane Durazane 1800, polyacrylonitrile and polystyrene followed by an appropriate heat-treatment. Co nanoparticles with a remarkably low mass loading (4 wt%) were immobilized on the SiCN(O) fibres for efficient bifunctional catalytic activity towards OER/ORR. The catalysts exhibited ORR activity (onset potential (E0) of 0.83 V vs. RHE) and excellent stability (80 h) in alkaline medium. Concomitantly, the catalyst required only 1.67 V to drive a current density of 10 mA cm−2 in 1 M KOH for OER.