Researchers in China have developed a class of IrRu-N-C catalysts, with Ir and Ru single atoms uniformly populated in nitrogen–carbon composites, that exhibits excellent CO electrooxidation reaction (COOR) behavior as well as high-efficiency single-atom catalysis toward H2 electro-oxidation.
A paper on their work is published in Proceedings of the National Academy of Sciences (PNAS).
Conventionally, even a trace level of CO in hydrogen seriously poisons anode catalysts and leads to huge performance decay in a proton exchange membrane fuel cell (PEMFC). However, the traditionally invincible CO electro-oxidation process occurs easily on the new catalyst, with COOR initiating at nearly 0 mV versus reversible hydrogen electrode at ambient temperature.
This endows the catalyst with superb CO antipoisoning properties in PEMFCs at ultralow noble metal loadings.
With a small amount of metal (24 μgmetal⋅cm−2) used in the anode, the H2 fuel cell performs its peak power density at 1.43 W⋅cm−2. When operating with pure CO, this catalyst exhibits its maximum current density at 800 mA⋅cm−2, while the Pt/C-based cell ceases to work. We attribute this exceptional catalytic behavior to the interplay between Ir and Ru single-atom centers, where the two sites act in synergy to favorably decompose H2O and to further facilitate CO activation.
These findings open up an avenue to conquer the formidable poisoning issue of PEMFCs.—Wang et al.
Xian Wang, Yang Li, Ying Wang, Hao Zhang, Zhao Jin, Xiaolong Yang, Zhaoping Shi, Liang Liang, Zhijian Wu, Zheng Jiang, Wei Zhang, Changpeng Liu, Wei Xing, Junjie Ge (2021) “Proton exchange membrane fuel cells powered with both CO and H2” Proceedings of the National Academy of Sciences doi: 10.1073/pnas.2107332118