Wan Liyang, Chen Weikun, Xu Hui, Wang Yucheng, Yuan Jiayin, Zhou Zhiyou, Sun Shigang
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative innovation center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen 361005, China.
ACS Appl Mater Interfaces. 2021 Sep 29;13(38):45661-45669. doi: 10.1021/acsami.1c14709. Epub 2021 Sep 15.
The structural tailoring of pores is essential to high-performance Fe/N/C electrocatalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. Current strategies for pore structure engineering are usually accompanied with a drastic change of the intrinsic activity-related surface, which may mask the real effects of the porous structure on ORR activity. Herein, a mild carbon dioxide (CO) etching method was used to flexibly tailor the pore structure of Fe/N/C electrocatalysts without drastic changes in their surface structure and property. In this way, via employing the Fe/N/C electrocatalysts as a model, the intrinsic impact of the pore structure on ORR activity was revealed. In addition, the CO etching method developed a high-quality electrocatalyst (sample Fe/N/C-5% CO) with polarization performance exceeding that of the commercial Pt/C catalyst in the fuel cell working voltage region (>0.65 V). This work will promote the ongoing intensive studies on the rational design of the pore structures in the Fe/N/C electrocatalysts.
对于质子交换膜燃料电池中氧还原反应（ORR）的高性能Fe/N/C电催化剂而言，孔结构的定向剪裁至关重要。当前用于孔结构工程的策略通常伴随着与本征活性相关表面的剧烈变化，这可能掩盖了多孔结构对ORR活性的实际影响。在此，采用温和的二氧化碳（CO）蚀刻方法灵活地剪裁Fe/N/C电催化剂的孔结构，而其表面结构和性质无剧烈变化。通过这种方式，以Fe/N/C电催化剂为模型，揭示了孔结构对ORR活性的本征影响。此外，CO蚀刻方法制备出了一种高质量的电催化剂（样品Fe/N/C-5% CO），其极化性能在燃料电池工作电压区域（>0.65 V）超过了商业Pt/C催化剂。这项工作将推动目前对Fe/N/C电催化剂中孔结构合理设计的深入研究。
