Nitrogen‐Doped Hierarchical Porous Carbons Derived from Sodium Alginate as Efficient Oxygen Reduction Reaction Electrocatalysts

The exploration of earth‐abundant and low‐cost eco‐friendly materials with an excellent electrocatalytic performance is crucial for sustainable energy development. In this work, 3 D N‐doped hierarchical porous carbon (NC) materials with an interconnected mesoporous/macroporous structure have been synthesized by the simple single‐step pyrolysis of naturally available sodium alginate in the presence of urea. The systematic investigation of the pyrolysis temperature on the performance in the oxygen reduction reaction in 0.1 m KOH solution indicates that the catalyst obtained at 900 °C (NC‐900) exhibits the best catalytic performance because of the high degree of graphitization and the unique hierarchical porous structure. Furthermore, NC‐900 exhibits an excellent durability and a remarkable resistance to methanol poisoning compared to Pt/C in alkaline solution. This work highlights the significance and potential of biomass‐derived hierarchical porous carbon materials for applications in energy conversion devices.