Yunfeng Chen , Darong He , Yaxin Liu , Ming Zhao , Jianli Wang , Yaoqiang Chen
{"title":"共掺杂Pt-LaMnO3催化剂的a位增强了NO的氧化活性","authors":"Yunfeng Chen , Darong He , Yaxin Liu , Ming Zhao , Jianli Wang , Yaoqiang Chen","doi":"10.1016/j.mcat.2025.115216","DOIUrl":null,"url":null,"abstract":"<div><div>Perovskite oxides are always applied in the reaction of NO oxidation to NO<sub>2</sub> for diesel exhaust after-treatment systems. Elemental substitution is commonly used to modify the perovskites to enhance their redox properties. In this work, a series of Pt-La<sub>1−x</sub>Co<sub>x</sub>MnO<sub>3</sub> was prepared with different contents of Co replacing La in LaMnO<sub>3</sub>. Pt-La<sub>0.8</sub>Co<sub>0.2</sub>MnO<sub>3</sub> exhibited outstanding NO oxidation activity at the fresh state (NO Conversion = 52.7 %) and at the aged state (NO Conversion = 44.7 %). XRD and TEM results verified partial Co doping into the lattice to replace La, while the other Co existed in the form of CoMn<sub>2</sub>O<sub>4</sub> phases. XPS, Raman, and EPR results showed that electron transformation occurring on the Co-O-Mn structure from the interface between LaMnO<sub>3</sub> and CoMn<sub>2</sub>O<sub>4</sub> led to more Mn<sup>3+</sup>, the Mn-O bonds were weakened, and oxygen vacancies increased to facilitate O<sub>2</sub> activation. Besides, NO-TPD and <em>in situ</em> DRIFTS confirmed that Co<sup>3+</sup> also served as NO adsorption and activation sites with the decline of Mn<sup>4+</sup>. The cooperative effort of increasing oxygen vacancies for O<sub>2</sub> and Co<sup>3+</sup> for NO adsorption and activation enhances the NO oxidation activity.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"583 ","pages":"Article 115216"},"PeriodicalIF":3.9000,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A-site of Co-doped Pt-LaMnO3 catalyst enhances NO oxidation activity\",\"authors\":\"Yunfeng Chen , Darong He , Yaxin Liu , Ming Zhao , Jianli Wang , Yaoqiang Chen\",\"doi\":\"10.1016/j.mcat.2025.115216\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Perovskite oxides are always applied in the reaction of NO oxidation to NO<sub>2</sub> for diesel exhaust after-treatment systems. Elemental substitution is commonly used to modify the perovskites to enhance their redox properties. In this work, a series of Pt-La<sub>1−x</sub>Co<sub>x</sub>MnO<sub>3</sub> was prepared with different contents of Co replacing La in LaMnO<sub>3</sub>. Pt-La<sub>0.8</sub>Co<sub>0.2</sub>MnO<sub>3</sub> exhibited outstanding NO oxidation activity at the fresh state (NO Conversion = 52.7 %) and at the aged state (NO Conversion = 44.7 %). XRD and TEM results verified partial Co doping into the lattice to replace La, while the other Co existed in the form of CoMn<sub>2</sub>O<sub>4</sub> phases. XPS, Raman, and EPR results showed that electron transformation occurring on the Co-O-Mn structure from the interface between LaMnO<sub>3</sub> and CoMn<sub>2</sub>O<sub>4</sub> led to more Mn<sup>3+</sup>, the Mn-O bonds were weakened, and oxygen vacancies increased to facilitate O<sub>2</sub> activation. Besides, NO-TPD and <em>in situ</em> DRIFTS confirmed that Co<sup>3+</sup> also served as NO adsorption and activation sites with the decline of Mn<sup>4+</sup>. The cooperative effort of increasing oxygen vacancies for O<sub>2</sub> and Co<sup>3+</sup> for NO adsorption and activation enhances the NO oxidation activity.</div></div>\",\"PeriodicalId\":393,\"journal\":{\"name\":\"Molecular Catalysis\",\"volume\":\"583 \",\"pages\":\"Article 115216\"},\"PeriodicalIF\":3.9000,\"publicationDate\":\"2025-05-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Molecular Catalysis\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2468823125004018\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Catalysis","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2468823125004018","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
A-site of Co-doped Pt-LaMnO3 catalyst enhances NO oxidation activity
Perovskite oxides are always applied in the reaction of NO oxidation to NO2 for diesel exhaust after-treatment systems. Elemental substitution is commonly used to modify the perovskites to enhance their redox properties. In this work, a series of Pt-La1−xCoxMnO3 was prepared with different contents of Co replacing La in LaMnO3. Pt-La0.8Co0.2MnO3 exhibited outstanding NO oxidation activity at the fresh state (NO Conversion = 52.7 %) and at the aged state (NO Conversion = 44.7 %). XRD and TEM results verified partial Co doping into the lattice to replace La, while the other Co existed in the form of CoMn2O4 phases. XPS, Raman, and EPR results showed that electron transformation occurring on the Co-O-Mn structure from the interface between LaMnO3 and CoMn2O4 led to more Mn3+, the Mn-O bonds were weakened, and oxygen vacancies increased to facilitate O2 activation. Besides, NO-TPD and in situ DRIFTS confirmed that Co3+ also served as NO adsorption and activation sites with the decline of Mn4+. The cooperative effort of increasing oxygen vacancies for O2 and Co3+ for NO adsorption and activation enhances the NO oxidation activity.
期刊介绍:
Molecular Catalysis publishes full papers that are original, rigorous, and scholarly contributions examining the molecular and atomic aspects of catalytic activation and reaction mechanisms. The fields covered are:
Heterogeneous catalysis including immobilized molecular catalysts
Homogeneous catalysis including organocatalysis, organometallic catalysis and biocatalysis
Photo- and electrochemistry
Theoretical aspects of catalysis analyzed by computational methods