Dynamic evolution and reversibility of single-atom Ni(II) active site in 1T-MoS2 electrocatalysts for hydrogen evolution
Dynamic evolution and reversibility of single-atom Ni(II) active site in 1T-MoS2 electrocatalysts for hydrogen evolution
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DOI：
10.1038/s41467-020-17904-z
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发表时间：
2020-08-17
影响因子：
16.6
通讯作者：
Huang, Jier
中科院分区：
文献类型：
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作者：
Pattengale, Brian;Huang, Yichao;Huang, Jier
1T-MoS2和单原子修饰类似物是一类极有前途的低成本析氢反应催化剂。然而，单原子的作用，无论是作为活性物质还是启动子，仍然模糊不清，尽管它对更有效的HER至关重要。在这项工作中，我们报告了Ni单原子作为1T-MoS2基面上的关键活性位点的明确鉴定（Ni@1T-MoS2），从而实现了高效的HER性能。通过原位x射线吸收光谱捕获了催化条件下Ni活性位点的中间结构，其中在碱性条件下观察到可逆的金属Ni (Ni-0)，而在酸性条件下Ni保持其局部结构。这些见解提供了对Ni@1T-MoS2 HER电催化剂的重要机理理解，并表明从这种原位研究中获得的理解对于开发高效的单原子修饰1T-MoS2电催化剂是必要的。虽然单原子催化将异质材料与分子的认识结合起来，但单原子的作用仍然是模糊的。在这里，作者通过原位x射线吸收光谱检查MoS2上的单个Ni，以揭示中间和催化活性物质。
1T-MoS2 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-MoS2 (Ni@1T-MoS2) 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-0) is observed in alkaline conditions whereas Ni remains in its local structure under acidic conditions. These insights provide crucial mechanistic understanding of Ni@1T-MoS2 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-MoS2 electrocatalysts. While single atom catalysis combines heterogeneous materials with molecular understanding, the role of the single atoms remains vague. Here, authors examine single Ni on MoS2 via in situ X-ray absorption spectroscopy to reveal the intermediate and catalytically active species.