Self-Template Synthesis of Atomically Dispersed Fe/N-Codoped Nanocarbon As Efficient Bifunctional Alkaline Oxygen Electrocatalyst

High performance and durable bifunctional oxygen electrocatalysts are of great importance for the commercial application of environmentally friendly and sustainable energy through electrochemical devices such as rechargeable Zn–air batteries and fuel cells. Highly distributed catalysts with maximum atomic utilization are considered to be a promising alternative for current noble-metal-based catalysts. Herein, a high performance and durable bifunctional oxygen electrocatalyst for both ORR and OER is synthesized by a facile self-template and polypyrrole encapsulation method. The super performance atomically dispersed Fe/N-codoped double shelled hollow carbon nanospheres (AD-Fe/N-C-900) catalyst has a special open porous double shell hollow structure which is beneficial to exposure of more Fe-Nx active sites for ORR and OER, and improves mass transfer, resulting in a fabulous bifunctional ORR/OER electrocatalytic activity (△E =0.655 V), which is better than the commercial Pt/C (△E =1.035 V) and the commercial IrO2 (△E =0.93 V), along with remark durability and long-term stability for the ORR in alkaline medium. Based on our results and analysis, the remarkable electrocatalytic activity of AD-Fe/N-C-900 might be attributed to the high content of mesopore, high density of Fe-Nx active sites, and robust double shell hollow structure. The novel design of the atomically dispersed Fe/N-codoped porous double shell hollow nanocarbon enable boosted oxygen catalyst by a facile method has certain enlightening effect on the design and development of other bifunctional electrocatalysts in the next generation reversible energy conversion systems. Our work provides a design idea for the synthesis of high activity and stability bifunctional atom-level distributed catalysts. Figure 1