Singlet oxygen (¹O₂) plays a crucial role in Fenton-like reactions due to its high efficiency and selectivity in removing trace organic pollutants from complex water matrices. Defect engineering, which allows the efficient exposure of active sites and optimization of electronic structures, has rapidly emerged as a fundamental strategy for enhancing ¹O₂ yield. Herein, we introduce tunable sulfur vacancy (V_S) density into Co₉S₈ catalysts for peroxymonosulfate (PMS) activation. The modulation of the octahedral Co (CoS₆) and tetrahedral Co (CoS₄) electronic structures by V_S triggers the unexpected selective generation of ¹O₂. The V_S/PMS system exhibits excellent resistance to interference and highly selective degradation of electron-donating organic pollutants. Experimental and theoretical calculations revealed a new evolutionary route for ¹O₂ involving two phases (Phase I: HSO₅⁻ → *O, Phase II: *O + HSO₅⁻ →*OO → ¹O₂). This study provides a molecular-level understanding of V_S-mediated catalytic selectivity for high-efficient decontamination applications.

单线态氧 ( ¹ O ₂ ) 在类芬顿反应中发挥着至关重要的作用，因为它在去除复杂水基质中的痕量有机污染物方面具有高效性和选择性。缺陷工程能够有效暴露活性位点并优化电子结构，已迅速成为提高¹ O ₂产率的基本策略。在此，我们将可调的硫空位（V _S）密度引入Co ₉ S ₈催化剂中用于过一硫酸盐（PMS）活化。_{V S对八面体 Co (CoS 6} ) 和四面体 Co (CoS ₄ ) 电子结构的调制^触发1 O ₂的意外选择性生成。V _S /PMS系统表现出优异的抗干扰性和对供电子有机污染物的高度选择性降解。^{实验和理论计算揭示了1} O ₂的新演化路线，涉及两个阶段（第一阶段：HSO ₅ ⁻ → *O，第二阶段：*O + HSO ₅ ⁻ →*OO → ¹ O ₂）。这项研究为高效净化应用提供了对 V _S介导的催化选择性的分子水平理解。