The Fe and N co-functionalized catalyst is controllably synthesized by three-step strategy. Prussian blue (PB) and poly 2,6-diaminopyridine (PDAP) are preferentially selected to synthesize a core-shell structure attributed to their advantageous properties. Under pyrolysis process, carbonized PDAP serves as a block layer to prevent Fe-based nanoparticles from aggregation and increase the content of N. By adjusting the thickness of shell and pyrolysis temperature, the catalytic activity can be optimized. The optimized catalyst exhibits good catalytic performance in terms of onset and half-wave potentials, limiting-diffusion current density and durability. Moreover, the relationship between structure and effect is analyzed. It is found that the optimal catalyst presents excellently active for ORR stemming from a comprehensive effect, containing higher density of active site, higher surface area, porosity structure, and good conductivity of catalyst.

A 3D graphene-like catalyst has been controllably synthesized using core-shell and pyrolysis strategy. The morphology and activity can be tailored by adjusting the thickness of shell and pyrolysis temperature. Importantly, the optimized catalyst shows excellently active for ORR in both alkaline and acidic media.

通过三步策略可控制地合成Fe和N共官能化催化剂。优先选择普鲁士蓝（PB）和聚2,6-二氨基吡啶（PDAP）来合成归因于其优越性能的核-壳结构。在热解过程中，碳化的PDAP充当阻挡层，以防止铁基纳米颗粒聚集并增加N的含量。通过调节壳的厚度和热解温度，可以优化催化活性。经过优化的催化剂在起始和半波电势，限制扩散电流密度和耐久性方面均表现出良好的催化性能。此外，分析了结构与效果之间的关系。发现最佳催化剂对ORR具有优异的活性，这是由综合作用引起的，

已使用核-壳和热解策略可控制地合成了3D石墨烯状催化剂。可以通过调节壳的厚度和热解温度来定制形态和活性。重要的是，优化的催化剂在碱性和酸性介质中均对ORR具有出色的活性。