Abstract Tapping into the potentialities of coals as valuable resources that can be transformed into state-of-the-art energy-related materials is now a burgeoning and fascinating research area, which accords with the clean utilization of coals. In the present work, coal-based porous nitrogen-doped carbon (CPNC) electrocatalysts toward the oxygen reduction reaction (ORR) at fuel cell cathodes have been easily prepared by the mechanochemistry-assisted strategy. Catalyst preparation combines the low-temperature pyrolysis with the high-temperature annealing, which guarantees nitrogen-containing substances sealed and confined in the carbon layers and skeletons and effectively converts them into nitrogen-relevant bonds, simultaneously regulating architectural features (e.g. specific surface areas, pore width distributions, defects and edges). The optimal metal-free CPNC electrocatalyst owns onset potentials of 0.97, 0.80 and 0.87 V, half-wave potentials of 0.84, 0.64 and 0.65 V, limiting current densities of 4.96, 4.60 and 4.90 mA cm−2, electron-transfer numbers of 3.93, 3.92 and 3.91, together with fine current stability and methanol tolerance, in 0.1 M KOH, 0.5 M H2SO4 and 0.1 M phosphate buffer solution (pH = 7.0), respectively. This is the first report on high-performance coal-based pH-universal oxygen reduction electrocatalysts, attributed to the effective trade-off between textural properties of catalysts (related to surface areas and pore structures) and the number of catalytic reaction sites (associated with nitrogen configuration distributions). Accordingly, this work has established the basis by which earth-abundant coals are readily converted into high-performance oxygen reduction carbonaceous electrocatalysts that are able to be integrated into various fuel cell test beds.

中文翻译：

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将煤转化为用于燃料电池的碳基 pH 通用氧还原催化剂

摘要 挖掘煤炭作为可转化为最先进的能源相关材料的宝贵资源的潜力，是符合煤炭清洁利用的新兴研究领域。在目前的工作中，通过机械化学辅助策略很容易制备了煤基多孔掺氮碳（CPNC）电催化剂，用于燃料电池阴极的氧还原反应（ORR）。催化剂制备将低温热解与高温退火相结合，保证含氮物质密封和限制在碳层和骨架中，并有效地将它们转化为与氮相关的键，同时调节结构特征（例如比表面积、孔宽度分布、缺陷和边缘）。最佳的无金属 CPNC 电催化剂具有 0.97、0.80 和 0.87 V 的起始电位，0.84、0.64 和 0.65 V 的半波电位，4.96、4.60 和 4.90 mA cm-2 的限制电流密度，电子转移数为 4.93 、3.92 和 3.91，以及良好的电流稳定性和甲醇耐受性，分别在 0.1 M KOH、0.5 M H2SO4 和 0.1 M 磷酸盐缓冲溶液（pH = 7.0）中。这是关于高性能煤基 pH 通用氧还原电催化剂的第一份报告，归因于催化剂结构特性（与表面积和孔结构相关）和催化反应位点数量（与氮构型分布）。因此，