Engineering the Local Coordination Environment and Density of FeN4 Sites by Mn Cooperation for Electrocatalytic Oxygen Reduction
Engineering the Local Coordination Environment and Density of FeN4 Sites by Mn Cooperation for Electrocatalytic Oxygen Reduction
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通过锰合作设计局部配位环境和 FeN4 位点密度以实现电催化氧还原
DOI：
10.1002/smll.202200911
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发表时间：
2022-04-01
期刊：
影响因子：
13.3
通讯作者：
Shi, Chuan
中科院分区：
文献类型：
--
作者：
Cai, Huizhu;Zhang, Guanghui;Shi, Chuan
FeN 4的单原子位（SAS）被阐明为氧还原反应（ORR）的最活跃的组分之一。通过设计局部配位环境和FeN 4位点的位点密度的有效策略对于进一步增强电催化ORR性能至关重要。本文报道了第二金属Mn与Fe的整合以构建具有增强的FeN 4活性中心密度和调制的电子结构的Fe&Mn/N-C催化剂。MnN 4中心的形成调节了FeN 4位的局部环境，并通过形成可能的FeN 4-O-MnN 4构型保留了更多的FeN 4嵌入在碳基体中。密度泛函理论计算表明，整体的ORR的能量势垒降低超过FeN 4-O-MnN 4部分。因此，Fe&Mn/N-C催化剂在碱性和酸性溶液中都表现出增强的ORR性能（半波电位为0.904和0.781V）。该工作提供了一种有效的策略，通过调节FeN 4活性位的局部电子结构和密度，通过Mn的协同作用来提高ORR活性和稳定性。
Single atom sites (SAS) of FeN4 are clarified as one of the most active components for the oxygen reduction reaction (ORR). Effective strategies by engineering the local coordination environment and site density of FeN4 sites are crucial to further enhance the electrocatalytic ORR performance. Herein, the integration of a second metal of Mn with Fe to construct Fe&Mn/N-C catalysts with enhanced density of FeN4 active sites and modulated electronic structure is reported. The formation of MnN4 centers modulates the local environment of FeN4 sites and reserves more FeN4 embedded in carbon substrate by forming the possible FeN4-O-MnN4 configurations. Density functional theory calculations demonstrate that the overall energy barrier of ORR is decreased over the FeN4-O-MnN4 moieties. Therefore, the Fe&Mn/N-C catalyst exhibits enhanced ORR performance both in alkaline and acidic solution (half-wave potentials are 0.904 and 0.781 V). This work provides an effective strategy by modulating the local electronic structure and density of FeN4 active sites to improve the ORR activity and stability through Mn cooperation.