{"title":"金属氧化物如何误导自旋捕获电子顺磁共振分析?","authors":"Jing-Hang Wu, and , Han-Qing Yu*, ","doi":"10.1021/acs.estlett.4c00155","DOIUrl":null,"url":null,"abstract":"<p >Limited by the detection techniques, the reactive species involved in catalytic water purification processes are difficult to be clarified. Spin-trapping electron paramagnetic resonance (EPR) analysis is recognized as a reliable tool for radical identification, in which 5,5-dimethyl-1-pyrroline-<i>N</i>-oxide (DMPO) is usually used as the radical trapper. However, it is questioned that the detection of adducts of DMPO definitively indicates the generation of radicals. In this work, the DMPO transformation caused by transition metal oxides is monitored by EPR, and abundant spin signals are observed. MnO<sub>2</sub>, Mn<sub>2</sub>O<sub>3</sub>, and NiO could oxidize DMPO into DMPOX through direct oxygen transfer. Besides, the dissolved transition metal ions could transform DMPO into misleading DMPO–OH and DMPO–R. The findings in this work, e.g., the interactions between DMPO and different metal oxides and the quenching behavior of the different pathways, would help with reliable identifications of reactive species in both engineered systems and natural environments.</p>","PeriodicalId":37,"journal":{"name":"Environmental Science & Technology Letters Environ.","volume":null,"pages":null},"PeriodicalIF":8.9000,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"How Do Metal Oxides Mislead Spin-Trapping Electron Paramagnetic Resonance Analysis?\",\"authors\":\"Jing-Hang Wu, and , Han-Qing Yu*, \",\"doi\":\"10.1021/acs.estlett.4c00155\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >Limited by the detection techniques, the reactive species involved in catalytic water purification processes are difficult to be clarified. Spin-trapping electron paramagnetic resonance (EPR) analysis is recognized as a reliable tool for radical identification, in which 5,5-dimethyl-1-pyrroline-<i>N</i>-oxide (DMPO) is usually used as the radical trapper. However, it is questioned that the detection of adducts of DMPO definitively indicates the generation of radicals. In this work, the DMPO transformation caused by transition metal oxides is monitored by EPR, and abundant spin signals are observed. MnO<sub>2</sub>, Mn<sub>2</sub>O<sub>3</sub>, and NiO could oxidize DMPO into DMPOX through direct oxygen transfer. Besides, the dissolved transition metal ions could transform DMPO into misleading DMPO–OH and DMPO–R. The findings in this work, e.g., the interactions between DMPO and different metal oxides and the quenching behavior of the different pathways, would help with reliable identifications of reactive species in both engineered systems and natural environments.</p>\",\"PeriodicalId\":37,\"journal\":{\"name\":\"Environmental Science & Technology Letters Environ.\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":8.9000,\"publicationDate\":\"2024-03-14\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Environmental Science & Technology Letters Environ.\",\"FirstCategoryId\":\"1\",\"ListUrlMain\":\"https://pubs.acs.org/doi/10.1021/acs.estlett.4c00155\",\"RegionNum\":2,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, ENVIRONMENTAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Science & Technology Letters Environ.","FirstCategoryId":"1","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.estlett.4c00155","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
How Do Metal Oxides Mislead Spin-Trapping Electron Paramagnetic Resonance Analysis?
Limited by the detection techniques, the reactive species involved in catalytic water purification processes are difficult to be clarified. Spin-trapping electron paramagnetic resonance (EPR) analysis is recognized as a reliable tool for radical identification, in which 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) is usually used as the radical trapper. However, it is questioned that the detection of adducts of DMPO definitively indicates the generation of radicals. In this work, the DMPO transformation caused by transition metal oxides is monitored by EPR, and abundant spin signals are observed. MnO2, Mn2O3, and NiO could oxidize DMPO into DMPOX through direct oxygen transfer. Besides, the dissolved transition metal ions could transform DMPO into misleading DMPO–OH and DMPO–R. The findings in this work, e.g., the interactions between DMPO and different metal oxides and the quenching behavior of the different pathways, would help with reliable identifications of reactive species in both engineered systems and natural environments.
期刊介绍:
Environmental Science & Technology Letters serves as an international forum for brief communications on experimental or theoretical results of exceptional timeliness in all aspects of environmental science, both pure and applied. Published as soon as accepted, these communications are summarized in monthly issues. Additionally, the journal features short reviews on emerging topics in environmental science and technology.