南开大学环境科学与工程学院展思辉教授团队提出了在单原子CoN2+2位点上过一硫酸盐近100%转化为单态氧的方法。 相关论文于2020年11月21日发表于国际顶尖学术期刊《德国应用化学》。

单原子CoN  4活性位点在过氧单硫酸根活化中表现出卓越的效率。然而，过氧化单硫酸盐活化过程中Con 4活性位点的确定和具体的单线态氧生成机理仍不明确。

在该研究中，研究人员提出了一种通过锚定在氮掺杂碳上的原子分散的钴来调节活性氧物种生成的策略。在实验和密度泛函数计算的辅助下，确定了活性位点 CoN 2+2 。单态氧是绝对优势的活性氧物种，所占比例为98.89%。与传统的CoN 4 构型不同，CoN 2+2 活性位点改变了PMS的活化途径，促进了单态氧的生成。由于弱的正 Co原子和CoN 2+2 配位引起的势垒，阻止了吸附在Co单原子上的过一硫酸盐的自发解离，导致了PMS在非自由基途径中的氧化和单态氧的同时产生。生成的单态氧在较宽的pH范围内对多种有机污染物表现出高效降解活性。

附：英文原文

Title: Almost 100% peroxymonosulfate conversion to singlet oxygen on single‐atom CoN2+2 sites

Author: Xueyue Mi, Pengfei Wang, Shizhe Xu, Lina Su, Hui Zhong, Haitao Wang, Yi Li, Sihui Zhan

Issue&Volume: 21 November 2020

Abstract: Single‐atom CoN  4  active sites have demonstrated excellent efficiency in peroxymonosulfate activation. However, the identification of CoN  4  active sites and the detailed singlet oxygen generation mechanism in peroxymonosulfate activation still remain ambiguous. In this study, we demonstrated a strategy to regulate the generation of reactive oxygen species by atomically dispersed cobalt anchored on nitrogen‐doped carbon. As assisted by experimental and DFT calculations, CoN  2+2  was the definite active sites. Singlet oxygen was the absolutely predominant reactive oxygen species that the proportion was 98.89%. Different from the traditional CoN  4  configuration, the CoN  2+2  active sites transformed the pathway of peroxymonosulfate activation and facilitated the singlet oxygen generation. Spontaneous dissociation of adsorbed peroxymonosulfate on Co single atoms was prevented due to the energy barriers caused by weak positive Co atoms and CoN  2+2  coordination, determining PMS oxidation in non‐radical pathway and simultaneous singlet oxygen generation. The generated singlet oxygen showed efficient activity for degradation of several organic pollutants in a broad pH range.

DOI: 10.1002/anie.202014472

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202014472