{"title":"Selectivity modulation in Fischer-Tropsch synthesis through reducibility control of cobalt-species containing HMS framework","authors":"T.A. Zepeda","doi":"10.1016/j.cattod.2024.115110","DOIUrl":null,"url":null,"abstract":"<div><div>Here reports the modulation of selectivity in Fischer-Tropsch synthesis through the control of cobalt reducibility within a hexagonal mesoporous silica (HMS) framework. Cobalt loading, varied from 3 % to 12.5 wt%, generated different surface and bulk cobalt species that interact variably with the support, significantly influencing their reducibility and the resultant catalytic behavior. This variation significantly affected the reducibility of the cobalt species, influencing on the catalytic behavior. The control of reducibility and stability of Co species is contingent on the cobalt loading. Higher cobalt content enhances the reducibility of Co species, shifting product selectivity from long-chain hydrocarbons to lighter olefins and oxygenates. At a TOS of 4 h, the active phase predominantly involves metallic Co species, while CO<sub>2</sub> and oxygenates formation is closely linked to the pair Co<sup>0</sup>-Co<sup>2+</sup> active phase. After a TOS of 120 h, samples with higher cobalt content (6.1–15.8 % wt.) exhibited notable deactivation and changes in selectivity and hydrocarbon distribution. These changes were associated with the formation of a Co<sub>2</sub>C phase, which inhibits methane formation and chain growth while enhancing the production of lower olefins and oxygenates through a synergistic interaction at the Co<sup>0</sup> and Co<sub>2</sub>C interface, also improves the WGS reaction, thereby increasing CO<sub>2</sub> selectivity.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"445 ","pages":"Article 115110"},"PeriodicalIF":5.2000,"publicationDate":"2024-10-23","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/S0920586124006047","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
Abstract
Here reports the modulation of selectivity in Fischer-Tropsch synthesis through the control of cobalt reducibility within a hexagonal mesoporous silica (HMS) framework. Cobalt loading, varied from 3 % to 12.5 wt%, generated different surface and bulk cobalt species that interact variably with the support, significantly influencing their reducibility and the resultant catalytic behavior. This variation significantly affected the reducibility of the cobalt species, influencing on the catalytic behavior. The control of reducibility and stability of Co species is contingent on the cobalt loading. Higher cobalt content enhances the reducibility of Co species, shifting product selectivity from long-chain hydrocarbons to lighter olefins and oxygenates. At a TOS of 4 h, the active phase predominantly involves metallic Co species, while CO2 and oxygenates formation is closely linked to the pair Co0-Co2+ active phase. After a TOS of 120 h, samples with higher cobalt content (6.1–15.8 % wt.) exhibited notable deactivation and changes in selectivity and hydrocarbon distribution. These changes were associated with the formation of a Co2C phase, which inhibits methane formation and chain growth while enhancing the production of lower olefins and oxygenates through a synergistic interaction at the Co0 and Co2C interface, also improves the WGS reaction, thereby increasing CO2 selectivity.
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.