Zhang Xiaoyan, Zhang Shan, Yang Yong, Wang Liguang, Mu Zijie, Zhu Haishuang, Zhu Xiaoqing, Xing Huanhuan, Xia Hongyin, Huang Bolong, Li Jing, Guo Shaojun, Wang Erkang
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Adv Mater. 2020 Mar;32(10):e1906905. doi: 10.1002/adma.201906905. Epub 2020 Jan 31.
Excavating and developing highly efficient and cost-effective nonnoble metal single-atom catalysts for electrocatalytic reactions is of paramount significance but still in its infancy. Herein, reported is a general NaCl template-assisted strategy for rationally designing and preparing a series of isolated transition metal single atoms (Fe/Co/Ni) anchored on honeycomb-like nitrogen-doped carbon matrix (M -HNC-T -T , M = Fe/Co/Ni, T = 500 °C, T = 850 °C). The resulting M -HNC-500-850 with M-N active sites exhibits superior capability for oxygen reduction reaction (ORR) with the half-wave potential order of Fe -HNC-500-850 > Co -HNC-500-850 > Ni -HNC-500-850, in which Fe -HNC-500-850 shows better performance than commercial Pt/C. Density functional theory calculations reveal a choice strategy that the strong p-d-coupled spatial charge separation results the Fe-N effectively merges active electrons for elevating d-band activity in a van-Hove singularity like character. This essentially generalizes an optimal electronic exchange-and-transfer (ExT) capability for boosting sluggish alkaline ORR activity. This work not only presents a universal strategy for preparing single-atom electrocatalyst to accelerate the kinetics of cathodic ORR but also provides an insight into the relationship between the electronic structure and the electrocatalytical activity.
挖掘和开发用于电催化反应的高效且具有成本效益的非贵金属单原子催化剂具有至关重要的意义，但仍处于起步阶段。在此，报道了一种通用的NaCl模板辅助策略，用于合理设计和制备一系列锚定在蜂窝状氮掺杂碳基质上的孤立过渡金属单原子（Fe/Co/Ni）（M-HNC-T-T，M = Fe/Co/Ni，T = 500 °C，T = 850 °C）。所得具有M-N活性位点的M-HNC-500-850表现出优异的氧还原反应（ORR）能力，半波电位顺序为Fe-HNC-500-850 > Co-HNC-500-850 > Ni-HNC-500-850，其中Fe-HNC-500-850的性能优于商业Pt/C。密度泛函理论计算揭示了一种选择策略，即强p-d耦合空间电荷分离导致Fe-N有效地合并活性电子，以提升类范霍夫奇点特征的d带活性。这从本质上概括了一种用于提高缓慢碱性ORR活性的最佳电子交换和转移（ExT）能力。这项工作不仅提出了一种制备单原子电催化剂以加速阴极ORR动力学的通用策略，还深入探讨了电子结构与电催化活性之间的关系。
