A complementary descriptor for elucidating selective PMS activation by iron single-atom catalysts with tunable interatomic distances.

Wang, Yifei; Sun, Xuedi; Wang, Hao; Wu, Yiyang; Ma, Yuqing; Wang, Ze; Zhu, Tingting; Wei, Jinshan et al. · Sci Adv · 2026

basic_science · Level V

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Abstract

The activation of peroxymonosulfate (PMS) for selective oxidant generation in advanced oxidation process is a sought objective when using single-atom catalysts (SACs) over conventional nanomaterials. However, challenges in controlling atomic-level morphology and understanding the intricate interplay between electronic and geometric properties that affect catalytic selectivity hinder rational material design. To address this issue, we developed a library of iron single-atom catalysts (FeSACs) featuring tunable interatomic distances ranging from 2.6 to 10.5 angstroms, facilitating the independent investigation of electronic and geometric effects. We propose a complementary descriptor (CD) integrating electronic effect index (<i>I</i><sub>EE</sub>) and geometric effect index (<i>I</i><sub>GE</sub>) in a weighted predictive framework. The CD strongly correlates with singlet oxygen (<sup>1</sup>O<sub>2</sub>) production in selective PMS activation by the FeSAC series. Specifically, the optimized FeSAC<sub>5.0</sub> delivers 94.2% <sup>1</sup>O<sub>2</sub> selectivity and nearly complete degradation of electron-rich micropollutants. This CD framework offers a universal strategy for the rational design of high-performance SACs grounded in electronic and geometric criteria.