Wu Peng Fei, Yang Yu Qi, Xi Hong Yan, Si Yang, Chu Yong Heng, Su Xiao Zhi, Yan Wen Sheng, You Ting Ting, Gao Yu Kun, Wang Yu, Chen Wen Xing, Huang Yu Ying, Yin Peng Gang
Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing, 100191, China.
School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
Small. 2024 Mar;20(9):e2306716. doi: 10.1002/smll.202306716. Epub 2023 Oct 20.
The interaction between catalyst and support plays an important role in electrocatalytic hydrogen evolution (HER), which may explain the improvement in performance by phase transition or structural remodeling. However, the intrinsic behavior of these catalysts (dynamic evolution of the interface under bias, structural/morphological transformation, stability) has not been clearly monitored, while the operando technology does well in capturing the dynamic changes in the reaction process in real time to determine the actual active site. In this paper, nitrogen-doped molybdenum atom-clusters on Ti C T (Mo /N-Ti C T ) is used as a model catalyst to reveal the dynamic evolution of Mo on Ti C T during the HER process. Operando X-ray absorption structure (XAS) theoretical calculation and in situ Raman spectroscopy showed that the Mo cluster structure evolves to a 6-coordinated monatomic Mo structure under working conditions, exposing more active sites and thus improving the catalytic performance. It shows excellent HER performance comparable to that of commercial Pt/C, including an overpotential of 60 mV at 10 mA cm , a small Tafel slope (56 mV dec ), and high activity and durability. This study provides a unique perspective for investigating the evolution of species, interfacial migration mechanisms, and sources of activity-enhancing compounds in the process of electroreduction.
催化剂与载体之间的相互作用在电催化析氢反应（HER）中起着重要作用，这可能解释了通过相变或结构重塑实现的性能提升。然而，这些催化剂的内在行为（偏压下界面的动态演变、结构/形态转变、稳定性）尚未得到清晰监测，而原位技术能够很好地实时捕捉反应过程中的动态变化，以确定实际的活性位点。本文中，TiCT上的氮掺杂钼原子簇（Mo/N-TiCT）被用作模型催化剂，以揭示HER过程中TiCT上Mo的动态演变。原位X射线吸收结构（XAS）理论计算和原位拉曼光谱表明，Mo簇结构在工作条件下演变为六配位单原子Mo结构，暴露出更多活性位点，从而提高了催化性能。它展现出与商业Pt/C相当的优异HER性能，包括在10 mA cm²时过电位为60 mV、较小的塔菲尔斜率（56 mV dec⁻¹）以及高活性和耐久性。该研究为研究电还原过程中物种的演变、界面迁移机制以及活性增强化合物的来源提供了独特视角。
