Meng Dapeng, Zheng Jingxuan, Guo Junxin, Zhang Anyu, Wang Zhao
National Engineering Research Center of Industry Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
Small. 2025 Mar;21(9):e2408146. doi: 10.1002/smll.202408146. Epub 2025 Jan 31.
Diatomic catalysts are promising for the electrochemical CO reduction reaction (CORR) due to their maximum atom utilization and the presence of multiple active sites. However, the atomic-scale design of diatomic catalysts and the elucidation of synergistic catalytic mechanisms between multiple active centers remain challenging. In this study, heteronuclear Fe─In diatomic sites anchored on nitrogen-doped carbon (FeIn DA/NC) are constructed. The FeIn DA/NC electrocatalyst achieves a CO Faradaic efficiency exceeding 90% across a wide range of applied potentials from -0.4 to -0.7 V, with a peak efficiency of 99.1% at -0.5 V versus the reversible hydrogen electrode. In situ, attenuated total reflection surface-enhanced infrared absorption spectroscopy and density functional theory calculations reveal that the synergistic interaction between Fe and In diatomic sites induce an asymmetric charge distribution, which promote the adsorption of CO at the Fe site and lowered the energy barrier for the formation of COOH. Moreover, the unique Fe─In diatomic site structure increase the adsorption energy of OH through a bridging interaction, which decrease the energy barrier for water dissociation and further promoted CORR activity.
双原子催化剂因其最大的原子利用率和多个活性位点的存在，在电化学CO还原反应（CORR）中具有广阔前景。然而，双原子催化剂的原子尺度设计以及多个活性中心之间协同催化机制的阐明仍然具有挑战性。在本研究中，构建了锚定在氮掺杂碳上的异核Fe─In双原子位点（FeIn DA/NC）。FeIn DA/NC电催化剂在-0.4至-0.7 V的宽应用电位范围内实现了超过90%的CO法拉第效率，相对于可逆氢电极，在-0.5 V时峰值效率为99.1%。原位衰减全反射表面增强红外吸收光谱和密度泛函理论计算表明，Fe和In双原子位点之间的协同相互作用诱导了不对称电荷分布，这促进了CO在Fe位点的吸附，并降低了COOH形成的能垒。此外，独特的Fe─In双原子位点结构通过桥连相互作用增加了OH的吸附能，这降低了水离解的能垒，并进一步促进了CORR活性。
