Enhancing the Electrochemical Oxygen Reduction Activity of PPy-Derived Porous Carbon through a Facile Ternary Doping Approach

Developing active and stable low-cost alternatives to Pt-based electrocatalysts for the oxygen reduction reaction (ORR) in electrochemical energy conversion and storage devices still remains a great challenge. Toward this approach, heteroatom-doped porous carbon catalysts form a promising class of cost-efficient, metal-free alternatives. Here, we report the design and synthesis of a B-, N-, and F-doped porous carbon catalyst (BNF-C) using the porous nitrogen-rich three-dimensional network of polypyrrole hydrogel. Our results indicate that the as-synthesized catalyst at 900 °C (BNF-C-900) featuring optimum physical and chemical attributes demonstrates excellent ORR performance in 0.1 M KOH with a half-wave potential ( E 1/2 ) of 0.810 V (vs RHE) along with good limiting current density and short-term stability by retaining ∼87% of its original current after 25 h of current–time response test at 0.7 V. Additionally, the catalyst demonstrates excellent 4e – selectivity toward ORR with high electron transfer number (∼3.90) and H 2 O 2 yield below 6.51% in the potential range 0.4–1.0 V. The facile design approach with unique 3D porous structure of the precursor can be employed for the convenient and scalable synthesis of various metal-free as well as metal-based catalysts for electrochemical applications.