Acetylene black carbons were activated under flowing CO₂ atmosphere at 900 °C for different treatment times. The impact of this heat treatment on the porosity, hydrophilicity, and surface oxygen groups was carefully examined. Longer periods of activation led to increases in the surface area and porosity of the samples. Pore size distributions of the samples showed an increase in micropores, followed by a rise in mesopores, which indicated the occurrence of pore widening with a longer activation period. When used as a microporous layer for H₂/air fuel cells, samples with higher levels of porosity showed, in general, reduced mass transport performance due to the formation of pooling locations for water. These results highlight the importance of textural pores in carbon structures on the water management in hydrogen fuel cell when operating under high humidity conditions.

中文翻译：

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碳孔隙率对质子交换膜燃料电池阴极微孔层性能的影响

乙炔黑炭在900°C的流动CO ₂气氛下进行了不同的处理时间。仔细检查了该热处理对孔隙率，亲水性和表面氧基团的影响。较长的活化时间导致样品的表面积和孔隙率增加。样品的孔尺寸分布显示微孔增加，随后中孔增加，这表明随着活化时间的延长，孔变宽。当用作H ₂的微孔层时空气燃料电池，孔隙率较高的样品通常显示出由于形成水的汇集位置而降低了传质性能。这些结果凸显了当在高湿度条件下运行时，碳结构中结构性孔隙对于氢燃料电池中水管理的重要性。