Wang Yang, Zhang Dongyu, Chen Ting, Su Caijie, Xie Yi, Wu Changzheng, Kornienko Nikolay
State Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei 230026, China.
Institute of Inorganic Chemistry, Department of Chemistry, University of Bonn, Bonn 53121, Germany.
Natl Sci Rev. 2025 May 20;12(8):nwaf198. doi: 10.1093/nsr/nwaf198. eCollection 2025 Aug.
Molecular catalysts facilitate electrochemical conversion by changing their oxidation states to transfer electrons. However, this redox-mediated mechanism features stepwise electron transfer and substrate activation in separate elementary steps, thereby resulting in an inherent loss in efficiency. Here, we synthesize a two-dimensional (2D) iron phthalocyanine (FePc) material and uncover its non-mediated electron transfer behavior in electrocatalysis, which overcomes the conventional redox-mediated limitation in the oxygen reduction reaction (ORR) pathway that molecular catalysts face. The 2D geometry enables the FePc molecules to be positioned within the electrochemical double layer, enabling electrons to directly transfer to oxygen reactants, prior to the Fe(II/III) redox. This functions in a manner akin to a metal catalyst thereby opening a redox-decoupled ORR mechanism. As a result, the reported 2D FePc molecular catalyst exhibits unprecedented ORR half-wave potential at 0.945 V vs. the reversible hydrogen electrode, achieving efficient application in zinc-air batteries and H/O fuel cells. These findings open new possibilities in voltage efficient, redox-decoupled molecular catalysis that integrates strengths of molecules and materials in one synergistic system.
分子催化剂通过改变其氧化态来转移电子，从而促进电化学转化。然而，这种氧化还原介导的机制在单独的基本步骤中具有逐步的电子转移和底物活化，从而导致效率的固有损失。在此，我们合成了一种二维（2D）铁酞菁（FePc）材料，并揭示了其在电催化中的非介导电子转移行为，这克服了分子催化剂在氧还原反应（ORR）途径中面临的传统氧化还原介导的限制。二维几何结构使FePc分子能够定位在电化学双层内，使电子能够在Fe（II/III）氧化还原之前直接转移到氧反应物上。这以类似于金属催化剂的方式起作用，从而开启了一种氧化还原解耦的ORR机制。结果，所报道的二维FePc分子催化剂在相对于可逆氢电极的0.945 V处表现出前所未有的ORR半波电位，在锌空气电池和氢/氧燃料电池中实现了高效应用。这些发现为电压高效、氧化还原解耦的分子催化开辟了新的可能性，该催化在一个协同系统中整合了分子和材料的优势。
