Chen Gongjin, Qiu Xiaoyi, Liu Shiyuan, Cui Yingdan, Sun Yan, Zhang Yan, Liu Yushen, Liu Guimei, Kim Yoonseob, Xing Wei, Wang Haijiang, Shao Minhua
Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, 999077, China.
Department of Mechanical and Energy Engineering, Key Laboratory of Energy Conversion and Storage Technologies, Southern University of Science and Technology, Shenzhen, Guangdong, China.
Angew Chem Int Ed Engl. 2025 Jun 24;64(26):e202503934. doi: 10.1002/anie.202503934. Epub 2025 May 2.
The utilization of transition metal-based catalysts as alternatives presents an attractive solution for enhancing the sluggish oxygen reduction reaction (ORR) and reducing costly platinum-based electrocatalysts in hydrogen fuel cells. Manganese-based nitrogen-carbon (Mn-N-C) is anticipated to exhibit durability due to its weaker Fenton reaction propensity. However, a key obstacle lies in boosting intrinsic electrocatalytic activity and increasing the density of Mn active sites, crucial for practical integration into fuel cell operations. Herein, a three-step method is developed to synthesize atomically dispersed Mn-N-C materials with a rich mesoporous structure as highly effective ORR catalysts. The high Mn loading (3.42 wt%) promotes the generation of Duo-MnN active sites, demonstrating outstanding performance and durability for fuel cells. Specifically, the exceptional performance of proton exchange membrane fuel cells (PEMFC) reaches 649 mW cm and anion exchange membrane fuel cells (AEMFC) achieves 770 mW cm. Notably, the durability of the Mn-N-C catalyst in PEMFC is reported for the first time, showing only 18.4% decay after 30 000 square-wave cycles. This work provides a unique perspective and a systematic design strategy for building feasible nonprecious metal catalysts with a high active site density, addressing the challenges of inefficiency and performance limitations across various electrocatalytic applications.
使用过渡金属基催化剂作为替代品，为增强氢燃料电池中缓慢的氧还原反应（ORR）和减少昂贵的铂基电催化剂提供了一个有吸引力的解决方案。基于锰的氮碳（Mn-N-C）由于其较弱的芬顿反应倾向，有望表现出耐久性。然而，一个关键障碍在于提高其本征电催化活性和增加锰活性位点的密度，这对于实际集成到燃料电池运行中至关重要。在此，开发了一种三步法来合成具有丰富介孔结构的原子分散的Mn-N-C材料，作为高效的ORR催化剂。高锰负载量（3.42 wt%）促进了双锰氮活性位点的生成，展示了燃料电池出色的性能和耐久性。具体而言，质子交换膜燃料电池（PEMFC）的卓越性能达到649 mW/cm²，阴离子交换膜燃料电池（AEMFC）达到770 mW/cm²。值得注意的是，首次报道了Mn-N-C催化剂在PEMFC中的耐久性，在30000次方波循环后仅衰减18.4%。这项工作为构建具有高活性位点密度的可行非贵金属催化剂提供了独特的视角和系统的设计策略，解决了各种电催化应用中的效率低下和性能限制挑战。
