Pattengale Brian, Huang Yichao, Yan Xingxu, Yang Sizhuo, Younan Sabrina, Hu Wenhui, Li Zhida, Lee Sungsik, Pan Xiaoqing, Gu Jing, Huang Jier
Department of Chemistry, Marquette University, Milwaukee, WI, 53201, USA.
Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, 92181, USA.
Nat Commun. 2020 Aug 17;11(1):4114. doi: 10.1038/s41467-020-17904-z.
1T-MoS and single-atom modified analogues represent a highly promising class of low-cost catalysts for hydrogen evolution reaction (HER). However, the role of single atoms, either as active species or promoters, remains vague despite its essentiality toward more efficient HER. In this work, we report the unambiguous identification of Ni single atom as key active sites in the basal plane of 1T-MoS (Ni@1T-MoS) that result in efficient HER performance. The intermediate structure of this Ni active site under catalytic conditions was captured by in situ X-ray absorption spectroscopy, where a reversible metallic Ni species (Ni) is observed in alkaline conditions whereas Ni remains in its local structure under acidic conditions. These insights provide crucial mechanistic understanding of Ni@1T-MoS HER electrocatalysts and suggest that the understanding gained from such in situ studies is necessary toward the development of highly efficient single-atom decorated 1T-MoS electrocatalysts.
1T相二硫化钼（1T-MoS）及其单原子修饰的类似物是一类极具潜力的低成本析氢反应（HER）催化剂。然而，单原子作为活性物种或促进剂的作用，尽管对更高效的析氢反应至关重要，但仍不明确。在这项工作中，我们明确鉴定出镍单原子是1T-MoS基面中的关键活性位点（Ni@1T-MoS），这使得其具有高效的析氢反应性能。通过原位X射线吸收光谱捕获了该镍活性位点在催化条件下的中间结构，其中在碱性条件下观察到可逆的金属镍物种（Ni），而在酸性条件下镍保留在其局部结构中。这些见解为Ni@1T-MoS析氢反应电催化剂提供了关键的机理理解，并表明从这种原位研究中获得的认识对于开发高效的单原子修饰1T-MoS电催化剂是必要的。
