Xiong Yin, Yang Yao, DiSalvo Francis J, Abruña Héctor D
Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853 , United States.
J Am Chem Soc. 2019 Jul 10;141(27):10744-10750. doi: 10.1021/jacs.9b03561. Epub 2019 Jun 27.
The oxygen reduction reaction (ORR) is considered the cornerstone for regenerative energy conversion devices involving fuel cells and electrolyzers. The development of non-precious-metal electrocatalysts is of paramount importance for their large-scale commercialization. Here, Co-Fe binary alloy embedded bimetallic organic frameworks (BMOF)s based on carbon nanocomposites have been designed with a compositionally optimized template, by a facile host-guest strategy, for ORR in alkaline media. The electrocatalyst exhibits promising electrocatalytic activity for ORR with a half-wave potential of 0.89 V in 0.1 M NaOH, comparable to state-of-the-art Pt/C electrocatalysts. More importantly, it exhibits robust durability after 30 000 potential cycles. Scanning transmission electron microscopy (STEM) and quantitative energy-dispersive X-ray (EDX) spectroscopy suggest that the Co-Fe alloy nanoparticles have a homogeneous elemental distribution of Co and Fe at the atomic-scale optimized BMOF and Co/Fe ratio of 9:1. The long-term durability is attributed to its ability to maintain its structural and compositional integrity after the cycling process, as evidenced by STEM-EDX analysis. This work provides valuable insights into the design and fabrication of novel platinum-group-metals-free highly active ORR electrocatalysts in alkaline media.
氧还原反应（ORR）被认为是涉及燃料电池和电解槽的可再生能源转换装置的基石。开发非贵金属电催化剂对其大规模商业化至关重要。在此，通过简便的主客体策略，基于碳纳米复合材料设计了一种基于组成优化模板的钴铁二元合金嵌入双金属有机框架（BMOF），用于碱性介质中的ORR。该电催化剂对ORR表现出有前景的电催化活性，在0.1 M NaOH中的半波电位为0.89 V，与最先进的Pt/C电催化剂相当。更重要的是，在30000次电位循环后它表现出强大的耐久性。扫描透射电子显微镜（STEM）和定量能量色散X射线（EDX）光谱表明，钴铁合金纳米颗粒在原子尺度优化的BMOF和钴/铁比为9:1时具有均匀的钴和铁元素分布。长期耐久性归因于其在循环过程后保持结构和组成完整性的能力，STEM-EDX分析证明了这一点。这项工作为在碱性介质中设计和制造新型无铂族金属的高活性ORR电催化剂提供了有价值的见解。
