Hao Zhang, Huinan Li, Pengyi Zhang, Tingxia Hu, Xianjie Wang
{"title":"Highly active copper-intercalated weakly crystallized δ-MnO2 for low-temperature oxidation of CO in dry and humid air","authors":"Hao Zhang, Huinan Li, Pengyi Zhang, Tingxia Hu, Xianjie Wang","doi":"10.1007/s11783-024-1822-5","DOIUrl":null,"url":null,"abstract":"<p>Copper intercalated birnessite MnO<sub>2</sub> (δ-MnO<sub>2</sub>) with weak crystallinity and high specific surface area (421 m<sup>2</sup>/g) was synthesized by a one-pot redox method and investigated for low-temperature CO oxidation. The molar ratio of Cu/Mn was as high as 0.37, which greatly weakened the Mn-O bond and created a lot of low-temperature active oxygen species. <i>In situ</i> DRIFTS revealed strong bonding of copper ions with CO. As-synthesized MnO<sub>2</sub>-150Cu achieved 100% conversion of 250 ppm CO in normal air (3.1 ppm H<sub>2</sub>O) even at −10 °C under the weight-hourly space velocity (WHSV) of 150 L/(g·h). In addition, it showed high oxygen storage capacity to oxidize CO in inert atmosphere. Though the concurrent moisture in air significantly inhibited CO adsorption and its conversion at ambient temperature, MnO<sub>2</sub>-150Cu could stably convert CO in 1.3% moisture air at 70 °C owing to its great low-temperature activity and reduced competitive adsorption of water with increased temperature. This study discovers the excellent low-temperature activity of weakly crystallized δ-MnO<sub>2</sub> induced by high content intercalated copper ions.\n</p>","PeriodicalId":12720,"journal":{"name":"Frontiers of Environmental Science & Engineering","volume":"22 1","pages":""},"PeriodicalIF":6.1000,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers of Environmental Science & Engineering","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1007/s11783-024-1822-5","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Copper intercalated birnessite MnO2 (δ-MnO2) with weak crystallinity and high specific surface area (421 m2/g) was synthesized by a one-pot redox method and investigated for low-temperature CO oxidation. The molar ratio of Cu/Mn was as high as 0.37, which greatly weakened the Mn-O bond and created a lot of low-temperature active oxygen species. In situ DRIFTS revealed strong bonding of copper ions with CO. As-synthesized MnO2-150Cu achieved 100% conversion of 250 ppm CO in normal air (3.1 ppm H2O) even at −10 °C under the weight-hourly space velocity (WHSV) of 150 L/(g·h). In addition, it showed high oxygen storage capacity to oxidize CO in inert atmosphere. Though the concurrent moisture in air significantly inhibited CO adsorption and its conversion at ambient temperature, MnO2-150Cu could stably convert CO in 1.3% moisture air at 70 °C owing to its great low-temperature activity and reduced competitive adsorption of water with increased temperature. This study discovers the excellent low-temperature activity of weakly crystallized δ-MnO2 induced by high content intercalated copper ions.
期刊介绍:
Frontiers of Environmental Science & Engineering (FESE) is an international journal for researchers interested in a wide range of environmental disciplines. The journal''s aim is to advance and disseminate knowledge in all main branches of environmental science & engineering. The journal emphasizes papers in developing fields, as well as papers showing the interaction between environmental disciplines and other disciplines.
FESE is a bi-monthly journal. Its peer-reviewed contents consist of a broad blend of reviews, research papers, policy analyses, short communications, and opinions. Nonscheduled “special issue” and "hot topic", including a review article followed by a couple of related research articles, are organized to publish novel contributions and breaking results on all aspects of environmental field.