This study presents a nickel sulfide catalyst intercalated with sodium dodecyl sulfate (NiS₂-SDS/NF) synthesized through hydrothermal and pyrolytic methods. The unique “cabbage-like” morphology of NiS₂-SDS/NF enhances accessibility and charge transfer of active sites, confirmed by SEM, TEM, XRD, and XPS analyses. Electrochemical performance assessments reveal exceptional catalytic activity towards the oxygen evolution reaction and lignin oxidation, with NiS₂-SDS/NF demonstrating the highest current density and lowest Tafel slope among the tested catalysts. The lignosulfonate direct fuel cell utilizing NiS₂-SDS/NF as anode catalyst achieves a peak power density of 113 mW/cm² at 50 °C, with stable long-term performance and energy utilization rate of 70 %. This setup also converts lignosulfonate into oxalic acid with over 23 wt% yield and high selectivity. In-situ Raman and infrared spectroscopy elucidate the oxidation mechanism, showing the formation of NiOOH active sites and the cleavage of lignin macromolecules into aromatic and aliphatic acids. This work highlights the potential of NiS₂-SDS/NF for efficient lignin valorization and sustainable energy production, paving the way for future optimization and application of lignin-based fuel cells.

中文翻译：

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双功能木质素燃料电池：使用十二烷基硫酸盐插层 NiS2 阳极催化剂将发电与木质素磺酸盐增值相结合


本研究提出了一种通过水热和热解方法合成的与十二烷基硫酸钠 （NiS 2-SDS/NF） 嵌入的硫化镍催化剂。NiS 2-SDS/NF 独特的“卷心菜状”形态增强了活性位点的可及性和电荷转移，SEM、TEM、XRD 和 XPS 分析证实了这一点。电化学性能评估显示，NiS 2-SDS/NF 对析氧反应和木质素氧化具有优异的催化活性，其中 NiS 2-SDS/NF 在测试催化剂中表现出最高的电流密度和最低的塔菲尔斜率。利用 NiS 2-SDS/NF 作为负极催化剂的木质素磺酸盐直接燃料电池在 50 °C 时实现了 113 mW/cm² 的峰值功率密度，具有稳定的长期性能和 70 % 的能量利用率。该装置还将木质素磺酸盐转化为草酸，产率超过 23 wt%，选择性高。原位拉曼光谱和红外光谱阐明了氧化机制，显示了 NiOOH 活性位点的形成和木质素大分子裂解成芳香酸和脂肪族酸。这项工作突出了 NiS 2-SDS/NF 在高效木质素增值和可持续能源生产方面的潜力，为木质素燃料电池的未来优化和应用铺平了道路。