The coupling of C–S bonds is fundamental for the production of sulfur-containing chemical feedstocks in synthetic sulfur chemistry, while it remains a great challenge via heterogeneous catalysis over well-known transition metal-based catalysts. Herein, we identify that potassium polysulfides/oxy-sulfides/oxides (K–S(-O) species), the typical promoters, are the key active sites for coupling C–S bonds, while the vacancy-rich molybdenum disulfide (MoS₂) phases are found to be promoters to form the interfacial “K–S_active-Mo_v” species, which greatly reduce the activation energy barrier. The generation of the interfacial “K–S_active-Mo_v” sites is demonstrated by integrated aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM) and X-ray absorption fine structure (XAFS) spectroscopy. A structure–performance relationship between the active interfacial “K–S_active-Mo_v” sites and the C–S coupling activity is established through qualitative and quantitative analysis. In situ diffuse reflectance infrared Fourier transform spectroscopy combined with density functional theory (DFT) calculations further confirms the formation of key COSH* and C–S related intermediates and reveals the reaction mechanism of C–S bond formation at the molecular level.

中文翻译：

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鉴定钾相关物质作为 K-MoS2 材料上 C-S 键耦合的关键活性位点


C-S键的偶联是合成硫化学中生产含硫化学原料的基础，但通过多相催化对众所周知的过渡金属基催化剂仍然是一个巨大的挑战。在此，我们确定了典型的促进剂多硫化钾/氧硫化物/氧化物（K-S(-O)物种）是C-S键偶联的关键活性位点，而富含空位的二硫化钼（MoS < b0>）相被发现是形成界面“K–S _active -Mo _v ”物质的促进剂，大大降低了活化能垒。通过集成像差校正高角度环形暗场扫描透射电子显微镜（AC-HAADF- STEM）和 X 射线吸收精细结构（XAFS）光谱。通过定性和定量分析，建立了活性界面“K–S _active -Mo _v ”位点与C-S耦合活性之间的结构-性能关系。原位漫反射红外傅里叶变换光谱结合密度泛函理论（DFT）计算进一步证实了关键的COSH*和C-S相关中间体的形成，并揭示了分子水平上C-S键形成的反应机制。