{"title":"沸石 Y 上支撑的锰氧化物对臭氧催化氧化苯的影响","authors":"Xuerui Zheng , Hisahiro Einaga","doi":"10.1016/j.cattod.2024.115104","DOIUrl":null,"url":null,"abstract":"<div><div>Manganese oxide catalysts with different structures and loading levels were supported on zeolite Y catalysts using a dry impregnation method for the oxidation of low concentrations of benzene with ozone. X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS) studies revealed that manganese oxide was highly dispersed on the zeolite in a low oxidation state for those prepared with the acetate precursor, and highly oxidized and aggregated manganese oxide for those prepared with the nitrate precursor. In the reaction at 70 ℃, the benzene oxidation rate, CO<sub>2</sub> selectivity, and ozone/benzene decomposition ratio were independent of the manganese loading, manganese precursor, and zeolite Y porosity. These catalytic properties were found to be less dependent on the manganese oxide structure. A slight increase in the reaction temperature enhanced both the catalytic activity and the catalyst performance, while the presence of water vapor had no significant impact. The XAFS analysis of the spent catalysts indicated that during the benzene decomposition reaction, the structure of the manganese oxide loaded on the catalyst was altered, and its oxidation state was uniformly reduced.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"446 ","pages":"Article 115104"},"PeriodicalIF":5.2000,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effect of manganese oxides supported on zeolite Y on catalytic oxidation of benzene by ozone\",\"authors\":\"Xuerui Zheng , Hisahiro Einaga\",\"doi\":\"10.1016/j.cattod.2024.115104\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Manganese oxide catalysts with different structures and loading levels were supported on zeolite Y catalysts using a dry impregnation method for the oxidation of low concentrations of benzene with ozone. X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS) studies revealed that manganese oxide was highly dispersed on the zeolite in a low oxidation state for those prepared with the acetate precursor, and highly oxidized and aggregated manganese oxide for those prepared with the nitrate precursor. In the reaction at 70 ℃, the benzene oxidation rate, CO<sub>2</sub> selectivity, and ozone/benzene decomposition ratio were independent of the manganese loading, manganese precursor, and zeolite Y porosity. These catalytic properties were found to be less dependent on the manganese oxide structure. A slight increase in the reaction temperature enhanced both the catalytic activity and the catalyst performance, while the presence of water vapor had no significant impact. The XAFS analysis of the spent catalysts indicated that during the benzene decomposition reaction, the structure of the manganese oxide loaded on the catalyst was altered, and its oxidation state was uniformly reduced.</div></div>\",\"PeriodicalId\":264,\"journal\":{\"name\":\"Catalysis Today\",\"volume\":\"446 \",\"pages\":\"Article 115104\"},\"PeriodicalIF\":5.2000,\"publicationDate\":\"2024-10-24\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Catalysis Today\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0920586124005984\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catalysis Today","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0920586124005984","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}
引用次数: 0
摘要
采用干法浸渍法在沸石 Y 催化剂上支撑了不同结构和负载水平的氧化锰催化剂,用于用臭氧氧化低浓度苯。X 射线衍射(XRD)和 X 射线吸收精细结构(XAFS)研究表明,用醋酸盐前驱体制备的氧化锰以低氧化态高度分散在沸石上,而用硝酸盐前驱体制备的氧化锰则高度氧化和聚集。在 70 ℃ 的反应中,苯氧化率、二氧化碳选择性和臭氧/苯分解率与锰负载量、锰前体和沸石 Y 的孔隙率无关。这些催化特性对氧化锰结构的依赖性较小。反应温度略微升高可提高催化活性和催化剂性能,而水蒸气的存在则无明显影响。对废催化剂的 XAFS 分析表明,在苯分解反应过程中,催化剂上负载的氧化锰结构发生了改变,其氧化态均匀降低。
Effect of manganese oxides supported on zeolite Y on catalytic oxidation of benzene by ozone
Manganese oxide catalysts with different structures and loading levels were supported on zeolite Y catalysts using a dry impregnation method for the oxidation of low concentrations of benzene with ozone. X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS) studies revealed that manganese oxide was highly dispersed on the zeolite in a low oxidation state for those prepared with the acetate precursor, and highly oxidized and aggregated manganese oxide for those prepared with the nitrate precursor. In the reaction at 70 ℃, the benzene oxidation rate, CO2 selectivity, and ozone/benzene decomposition ratio were independent of the manganese loading, manganese precursor, and zeolite Y porosity. These catalytic properties were found to be less dependent on the manganese oxide structure. A slight increase in the reaction temperature enhanced both the catalytic activity and the catalyst performance, while the presence of water vapor had no significant impact. The XAFS analysis of the spent catalysts indicated that during the benzene decomposition reaction, the structure of the manganese oxide loaded on the catalyst was altered, and its oxidation state was uniformly reduced.
期刊介绍:
Catalysis Today focuses on the rapid publication of original invited papers devoted to currently important topics in catalysis and related subjects. The journal only publishes special issues (Proposing a Catalysis Today Special Issue), each of which is supervised by Guest Editors who recruit individual papers and oversee the peer review process. Catalysis Today offers researchers in the field of catalysis in-depth overviews of topical issues.
Both fundamental and applied aspects of catalysis are covered. Subjects such as catalysis of immobilized organometallic and biocatalytic systems are welcome. Subjects related to catalysis such as experimental techniques, adsorption, process technology, synthesis, in situ characterization, computational, theoretical modeling, imaging and others are included if there is a clear relationship to catalysis.