Chen Shanyong, Luo Tao, Wang Jingyu, Xiang Jiaqi, Li Xiaoqing, Ma Chao, Kao Cheng-Wei, Chan Ting-Shan, Liu You-Nian, Liu Min
Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physics, Central South University, 410083, Changsha, China.
Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, 410083, Changsha, China.
Angew Chem Int Ed Engl. 2025 Feb 3;64(6):e202418713. doi: 10.1002/anie.202418713. Epub 2024 Nov 19.
In oxygen reduction reaction to HO via two-electron pathway (2e ORR), adsorption strength of oxygen-containing intermediates determines both catalytic activity and selectivity. However, it also causes activity-selectivity trade-off. Herein, we propose a novel strategy through modulating the interaction between protons and *OOH intermediates to break the activity-selectivity trade-off for highly active and selective 2e ORR. Taking the typical cobalt-nitrogen-carbon single-atom catalyst as an example, boron heteroatoms doped into second coordination sphere of CoN (Co-NBC) increase proton affinity on catalyst surface, facilitating proton attack on the former oxygen of *OOH and thereby promoting HO formation. As a result, Co-NBC simultaneously achieves prominent 2e ORR activity and selectivity in acid with onset potential of 0.724 V vs. RHE and HO selectivity of 94 %, surpassing most reported catalysts. Furthermore, Co-NBC exhibits a remarkable HO productivity of 202.7 mg cm h and a remarkable stability of 60 h at 200 mA cm in flow cell. This work provides new insights into resolving activity-selectivity trade-off in electrocatalysis.
在通过双电子途径（2e ORR）将氧还原为HO的反应中，含氧中间体的吸附强度决定了催化活性和选择性。然而，这也导致了活性-选择性之间的权衡。在此，我们提出了一种新策略，即通过调节质子与OOH中间体之间的相互作用，来打破活性-选择性之间的权衡，以实现高活性和高选择性的2e ORR。以典型的钴-氮-碳单原子催化剂为例，掺杂到CoN第二配位层中的硼杂原子（Co-NBC）增加了催化剂表面的质子亲和力，促进质子攻击OOH的前一个氧原子，从而促进HO的形成。结果，Co-NBC在酸性条件下同时实现了显著的2e ORR活性和选择性，相对于可逆氢电极（RHE）的起始电位为0.724 V，HO选择性为94%，超过了大多数已报道的催化剂。此外，Co-NBC在流动池中表现出202.7 mg cm h的显著HO产率和在200 mA cm下60 h的显著稳定性。这项工作为解决电催化中的活性-选择性权衡提供了新的见解。
