Dual-template induced multi-scale porous Fe@FeNC oxygen reduction catalyst for high-performance electrochemical devices

The oxygen reduction reaction (ORR), as a key semi-reaction in various electrochemical conversions, was widely studied. The FeNC catalyst showed great potential to replace precious Pt as the ORR catalyst. The multi-scale porous structure was crucial for the catalytic activity of the FeNC catalyst due to the discrete distribution of active sites. Therefore, a dual-template strategy was developed using solid NaCl as the hard template and self-polymerized resin as the soft template to construct a smooth multi-scale porous FeNC (FeNC-DT) catalyst with embedded metallic Fe. The as-prepared catalyst exhibited a half-wave potential of 0.954 V vs. a reversible hydrogen electrode under alkaline conditions. The corresponding zinc-air battery and direct methanol fuel cell (DMFC) using FeNC-DT as the catalyst performed superior to the precious-metal-based catalysts in power density. Especially, the self-breathing DMFC achieved a maximum power of 23 mW/cm(2), indicating a great application prospect of the FeNC-DT catalyst in actual electrochemical devices.