The development of efficient and durable catalysts is critical for the commercialization of fuel cells, as the catalysts’ durability and reactivity dictate their ultimate lifetime and activity. In this work, amorphous silicon-based ceramics (Si–C–N and Si–Al–C–N) and TiN@Si–Al–C–N nanocomposites were developed using a precursor derived ceramics approach. In TiN@Si–Al–C–N nanocomposites, TiN nanocrystals (with sizes in the range of 5–12 nm) were effectively anchored on an amorphous Si–Al–C–N support. The nanocomposites were found to be mesoporous in nature and exhibited a surface area as high as 132 m²/g. The average pore size of the nanocomposites was found to increase with an increase in the pyrolysis temperature, and a subsequent graphitization of free carbon was observed as revealed from the Raman spectra. The ceramics were investigated for electrocatalytic activity toward the oxygen reduction reaction using the rotating disk electrode method. The TiN@Si–Al–C–N nanocomposites showed an onset potential of 0.7 V versus reversible hydrogen electrode for oxygen reduction, which seems to indicate a 4-electron pathway at the pyrolysis temperature of 1000°C in contrast to a 2-electron pathway exhibited by the nanocomposites pyrolyzed at 750°C via the Koutecky–Levich plot.

中文翻译：

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用于氧还原反应的前体衍生 TiN@Si–Al–C–N 陶瓷纳米复合材料的合成与表征

开发高效耐用的催化剂对于燃料电池的商业化至关重要，因为催化剂的耐用性和反应性决定了它们的最终寿命和活性。在这项工作中，使用前体衍生陶瓷方法开发了非晶硅基陶瓷（Si-C-N 和 Si-Al-C-N）和 TiN@Si-Al-C-N 纳米复合材料。在 TiN@Si–Al–C–N 纳米复合材料中，TiN 纳米晶体（尺寸在 5–12 nm 范围内）有效地固定在非晶 Si–Al–C–N 载体上。发现纳米复合材料本质上是介孔的，表面积高达 132 m ²/G。发现纳米复合材料的平均孔径随着热解温度的升高而增加，并且从拉曼光谱中观察到随后的游离碳石墨化。使用旋转圆盘电极法研究陶瓷对氧还原反应的电催化活性。TiN@Si–Al–C–N 纳米复合材料显示出 0.7 V 的起始电位与可逆氢电极相比，用于氧还原，这似乎表明在 1000°C 的热解温度下是 4 电子路径，而不是 2 电子路径通过 Koutecky-Levich 图，纳米复合材料在 750°C 下热解所展示的途径。