Chen Zhen, Liu Jiankang, Li Jianpeng, Zhang Yueteng, Yang Jia, Li Jun, Wang Zhiyuan, Liu Zhongyi, Zang Shuang-Quan
Henan Institute of Advanced Technology, State Key Laboratory of Coking Coal Resources Green Exploitation, and College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China.
The Pathophysiology Department, School of Basic Medical Sciences, Cancer Chemoprevention International Collaboration Laboratory, Zhengzhou University, Zhengzhou, 450001, China.
Angew Chem Int Ed Engl. 2025 Aug 11;64(33):e202506845. doi: 10.1002/anie.202506845. Epub 2025 Jun 24.
Single-atom catalysts (SACs) have been widely investigated and regarded as promising electrocatalysts for carbon dioxide reduction. However, studies on the impact of coordinated-nitrogen species in the active center on the spin state and catalytic activity remain scarce. Herein, two single Ni atom electrocatalysts with distinct pyridinic-N and pyrrolic-N coordination through a rapid Joule-heating method that preserves precursor nitrogen configurations. Magnetic susceptibility measurements reveal that pyridinic-N induces a high-spin state in Ni centers, while pyrrolic-N stabilizes a low-spin configuration. The high-spin Ni-N-C demonstrates an exceptional performance in electrocatalytic CO reduction, achieving 98.8% CO Faradaic efficiency in H-cells and maintaining >99% Faradaic efficiency at industrial current densities (≥250 mA cm) across alkaline, neutral, and acidic electrolytes in a gas-diffusion flow cell. A maximum power density of 1.89 mW cm and excellent charge-discharge cyclability also achieve in zinc-CO battery, further demonstrating the applicability of Ni-N-C. Theoretical calculations demonstrate that the high-spin state enhances d-orbital dispersion, strengthening hybridization with π* orbital of CO and stabilizing *COOH intermediates, thereby accelerating CO activation. This study not only establishes a novel strategy for spin-state engineering through coordination control but also advances scalable electrocatalyst design for efficient carbon cycling.
单原子催化剂（SACs）已被广泛研究，并被视为用于二氧化碳还原的有前景的电催化剂。然而，关于活性中心中配位氮物种对自旋态和催化活性影响的研究仍然很少。在此，通过一种保留前驱体氮构型的快速焦耳加热方法，制备了两种具有不同吡啶氮和吡咯氮配位的单镍原子电催化剂。磁化率测量表明，吡啶氮在镍中心诱导出高自旋态，而吡咯氮则稳定了低自旋构型。高自旋的Ni-N-C在电催化CO还原中表现出优异的性能，在H型电池中实现了98.8%的CO法拉第效率，并且在气体扩散流动池中，在碱性、中性和酸性电解质中，在工业电流密度（≥250 mA cm）下保持>99%的法拉第效率。在锌-CO电池中还实现了1.89 mW cm的最大功率密度和优异的充放电循环稳定性，进一步证明了Ni-N-C的适用性。理论计算表明，高自旋态增强了d轨道色散，加强了与CO的π轨道的杂化，并稳定了COOH中间体，从而加速了CO的活化。这项研究不仅通过配位控制建立了一种自旋态工程的新策略，还推动了用于高效碳循环的可扩展电催化剂设计。
