Laboratory for Inorganic Materials and Catalysis, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands.
Netherlands Organization for Scientific Research (NWO), The European Synchrotron Radiation Facility (ESRF), CS40220, 38043, Grenoble Cedex 9, France.
ChemSusChem. 2019 Oct 8;12(19):4383-4389. doi: 10.1002/cssc.201901811. Epub 2019 Aug 8.
Molybdenum disulfide (MoS ) and related transition metal chalcogenides can replace expensive precious metal catalysts such as Pt for the hydrogen evolution reaction (HER). The relations between the nanoscale properties and HER activity of well-controlled 2H and Li-promoted 1T phases of MoS , as well as an amorphous MoS phase, have been investigated and a detailed comparison is made on Mo-S and Mo-Mo bond analysis under operando HER conditions, which reveals a similar bond structure in 1T and amorphous MoS phases as a key feature in explaining their increased HER activity. Whereas the distinct bond structure in 1T phase MoS is caused by Li intercalation and disappears under harsh HER conditions, amorphous MoS maintains its intrinsic short Mo-Mo bond feature and, with that, its high HER activity. Quantum-chemical calculations indicate similar electronic structures of small MoS clusters serving as models for amorphous MoS and the 1T phase MoS , showing similar Gibbs free energies for hydrogen adsorption (ΔG ) and metallic character.
二硫化钼（MoS ）和相关的过渡金属硫属化物可以替代昂贵的贵金属催化剂，如 Pt，用于析氢反应（HER）。本文研究了经过良好控制的 2H 和 Li 促进的 1T 相 MoS 以及非晶态 MoS 相的纳米特性与 HER 活性之间的关系，并在 HER 条件下对 Mo-S 和 Mo-Mo 键分析进行了详细比较，揭示了 1T 和非晶态 MoS 相中类似的键结构是解释其 HER 活性增强的关键特征。然而，1T 相 MoS 中独特的键结构是由 Li 插层引起的，并且在苛刻的 HER 条件下会消失，而非晶态 MoS 则保持其内在的短 Mo-Mo 键特征，从而保持其高的 HER 活性。量子化学计算表明，作为非晶态 MoS 和 1T 相 MoS 模型的小 MoS 簇具有相似的电子结构，表现出相似的氢吸附吉布斯自由能（ΔG ）和金属特性。
