The development of highly efficient metal-free electrocatalysts towards the oxygen reduction reaction (ORR) is of vital importance for the large-scale application of fuel cell technologies. Herein, we demonstrate a facile and effective strategy for the controllable synthesis of nitrogen and phosphorus co-doped hierarchically porous carbon (N,P-HPC) electrocatalysts by pyrolyzing phytic acid (PA) and dicyandiamide (DCDA) with nitrogen-doped hierarchically porous carbon (NHPC) derived from cattle bones. The results show that optimal N and P co-doping plays an important role in enhancing the ORR catalytic activity of carbon-based electrocatalysts. The optimized N,P-HPC with a high content of N (3.2 at%) and P (4.0 at%) exhibits remarkable ORR activity with an onset potential of 0.924 V (comparable to commercial Pt/C), a half-wave potential of 0.853 V (12 mV higher than that of Pt/C) and a kinetic current density of 38.2 mA cm⁻² at 0.8 V (1.9-times that of Pt/C) in alkaline electrolyte. Furthermore, the N,P-HPC electrocatalyst also demonstrates superior electrochemical stability and methanol tolerance in comparison with Pt/C. The excellent ORR performance of N,P-HPC can be attributed to the increased number of active sites, the favorable three-dimensional hierarchically porous structure and the large specific surface area (1516 m² g⁻¹). This attractive strategy opens a new avenue for the synthesis of highly efficient metal-free electrocatalysts for the ORR.

中文翻译：

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源自牛骨的氮和磷共掺杂分级多孔碳，是用于氧还原反应的高效无金属电催化剂†

面向氧还原反应（ORR）的高效无金属电催化剂的开发对于燃料电池技术的大规模应用至关重要。在这里，我们展示了通过热解植酸（PA）和双氰胺（DCDA）和氮掺杂的分级多孔碳，可控合成氮和磷共掺杂的分级多孔碳（N，P-HPC）电催化剂的简便有效的策略。 （NHPC）来自牛骨头。结果表明，最佳的N和P共掺杂在增强碳基电催化剂的ORR催化活性方面起着重要作用。经过优化的N，P-HPC具有较高的N（3.2 at％）和P（4.0 at％）含量，具有显着的ORR活性，起始电势为0.924 V（可与商业Pt / C相比），半波电势的0。碱性电解液中0.8 V（Pt / C的1.9倍）的^-2。此外，与Pt / C相比，N，P-HPC电催化剂还显示出优异的电化学稳定性和甲醇耐受性。N，P-HPC的出色ORR性能可以归因于活性位点数量的增加，有利的三维层次多孔结构和大的比表面积（1516 m ² g ^-1）。这一有吸引力的策略为ORR的高效无金属电催化剂的合成开辟了一条新途径。