Effects of preparation method as well as the addition of CuO x species on Co 3 O 4 catalysts towards preferential oxidation of CO in H 2 rich stream

Effects of preparation method as well as the addition of CuO x species on Co 3 O 4 catalysts towards preferential oxidation of CO in H 2 rich stream | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Effects of preparation method as well as the addition of CuO x species on Co 3 O 4 catalysts towards preferential oxidation of CO in H 2 rich stream Choene Clement Tsoke, Reineck Mhlaba, John Moma, Takalani Magadzu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7330203/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 19 Nov, 2025 Read the published version in Catalysis Surveys from Asia → Version 1 posted 7 You are reading this latest preprint version Abstract Copper doped on cobalt oxide-based catalysts prepared by hydrothermal and reflux methods were investigated for preferential oxidation of carbon monoxide (CO(PrOx) in hydrogen rich stream. The FTIR spectra of as-prepared catalysts showed the presence of Co 3+-O 2-and Co 2+-O 2-stretching vibrations arising from Co3O4 spinel crystal structure, as confirmed by the XRD, TEM, and H2-TPR data. The reflux prepared 5 wt.% CuOx/Co3O4 catalyst demonstrated a notable CO conversion of 94% at 40 o C, compared to its hydrothermal counterpart. The activity is correlated with strong Cu-Co interactions within the spinel matrix and the unique catalyst morphology. These favoured the formation of high surface oxygen vacancies and small crystallite size (~5.0 nm), contributing to large pore structure and higher BET surface area of 64.9 m 2 /g. The surface oxidation states of Cu and Co were revealed to consists of Cu + , Cu 2+ , Co 2+ and Co 3+ by the XPS spectra, which drove Cu + + Co 3+ ↔ Cu 2+ + Co 2+ redox synergy. A decrease in content of active species (Cu + and Co 3+) with time on stream was observed during CO(PrOx). The as prepared 5 wt% CuOx/Co3O4(Ref) catalyst showed good stability under dry and CO2 environments, and its activity deactivate in moisture environment. This work offers a novel strategy for preparation of active CO(PrOx) catalysts with the aim to promote adoption of proton exchange membrane fuel cell (PEMFC) technology. PEMFC CO(PrOx) Co3O4-based Spinel CuOx H2-rich Hydrothermal Reflux Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 19 Nov, 2025 Read the published version in Catalysis Surveys from Asia → Version 1 posted Editorial decision: Revision requested 11 Sep, 2025 Reviews received at journal 04 Sep, 2025 Reviewers agreed at journal 09 Aug, 2025 Reviewers invited by journal 09 Aug, 2025 Editor assigned by journal 09 Aug, 2025 Submission checks completed at journal 09 Aug, 2025 First submitted to journal 08 Aug, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7330203","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":498185643,"identity":"96399e73-d8f9-4d55-baf7-458bc001072a","order_by":0,"name":"Choene Clement Tsoke","email":"","orcid":"","institution":"University of Limpopo","correspondingAuthor":false,"prefix":"","firstName":"Choene","middleName":"Clement","lastName":"Tsoke","suffix":""},{"id":498185646,"identity":"c63fdf25-6439-40e6-826c-777cb67bd7ac","order_by":1,"name":"Reineck Mhlaba","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+ElEQVRIiWNgGAWjYFACxgYgkcDAIMHcwMzAYMPAR4IWRpCWNAY2Iq2CazlMWIt5e3Pbgw81aQy6sxsbPxfUnE9sY2B++IHhjx1OLTJnDrYbzjiWw2B252Cz9Ixjt4Fa2IwlGHiScWqRkEhsk+ZtqGAwu5HYIM3DBtLCYAYKDNxa5B+2Sf+FaGn+zfPvHFAL+zcGBoN6PLYwtkkzNuSAtACtazsA1MIDtCXhMG4tPIltkj3H0nhAWqxn9iUbtzHzFEskHDiOWwv78WcSP2qS5cxuJB++XfDNTrafvX3jhw9/qnFqgQEeBBPk8QSCGkbBKBgFo2AU4AMA3lRNzW+NHjkAAAAASUVORK5CYII=","orcid":"","institution":"University of Limpopo","correspondingAuthor":true,"prefix":"","firstName":"Reineck","middleName":"","lastName":"Mhlaba","suffix":""},{"id":498185648,"identity":"8a79282a-0669-4950-bb63-59370a434bbd","order_by":2,"name":"John Moma","email":"","orcid":"","institution":"University of Witwatersrand","correspondingAuthor":false,"prefix":"","firstName":"John","middleName":"","lastName":"Moma","suffix":""},{"id":498185649,"identity":"5809961b-5fa6-4c25-8256-f707ce1fcd03","order_by":3,"name":"Takalani Magadzu","email":"","orcid":"","institution":"University of Limpopo","correspondingAuthor":false,"prefix":"","firstName":"Takalani","middleName":"","lastName":"Magadzu","suffix":""}],"badges":[],"createdAt":"2025-08-08 21:23:08","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7330203/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7330203/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10563-025-09468-z","type":"published","date":"2025-11-19T15:58:53+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":96650418,"identity":"3da03744-8485-4c47-9a4b-272fc55e37ed","added_by":"auto","created_at":"2025-11-24 16:12:07","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1924377,"visible":true,"origin":"","legend":"","description":"","filename":"ManuscriptTsokeC.C08August2025.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7330203/v1_covered_f9e20771-5b4c-47b9-83d3-5fb9897212b7.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effects of preparation method as well as the addition of CuO x species on Co 3 O 4 catalysts towards preferential oxidation of CO in H 2 rich stream","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"catalysis-surveys-from-asia","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cats","sideBox":"Learn more about [Catalysis Surveys from Asia](http://link.springer.com/journal/10563)","snPcode":"10563","submissionUrl":"https://submission.nature.com/new-submission/10563/3","title":"Catalysis Surveys from Asia","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"PEMFC, CO(PrOx), Co3O4-based, Spinel, CuOx, H2-rich, Hydrothermal, Reflux","lastPublishedDoi":"10.21203/rs.3.rs-7330203/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7330203/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Copper doped on cobalt oxide-based catalysts prepared by hydrothermal and reflux methods were investigated for preferential oxidation of carbon monoxide (CO(PrOx) in hydrogen rich stream. The FTIR spectra of as-prepared catalysts showed the presence of Co 3+-O 2-and Co 2+-O 2-stretching vibrations arising from Co3O4 spinel crystal structure, as confirmed by the XRD, TEM, and H2-TPR data. The reflux prepared 5 wt.% CuOx/Co3O4 catalyst demonstrated a notable CO conversion of 94% at 40 o C, compared to its hydrothermal counterpart. The activity is correlated with strong Cu-Co interactions within the spinel matrix and the unique catalyst morphology. These favoured the formation of high surface oxygen vacancies and small crystallite size (~5.0 nm), contributing to large pore structure and higher BET surface area of 64.9 m 2 /g. The surface oxidation states of Cu and Co were revealed to consists of Cu + , Cu 2+ , Co 2+ and Co 3+ by the XPS spectra, which drove Cu + + Co 3+ ↔ Cu 2+ + Co 2+ redox synergy. A decrease in content of active species (Cu + and Co 3+) with time on stream was observed during CO(PrOx). The as prepared 5 wt% CuOx/Co3O4(Ref) catalyst showed good stability under dry and CO2 environments, and its activity deactivate in moisture environment. This work offers a novel strategy for preparation of active CO(PrOx) catalysts with the aim to promote adoption of proton exchange membrane fuel cell (PEMFC) technology.","manuscriptTitle":"Effects of preparation method as well as the addition of CuO x species on Co 3 O 4 catalysts towards preferential oxidation of CO in H 2 rich stream","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-14 06:41:47","doi":"10.21203/rs.3.rs-7330203/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-09-12T00:07:52+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-04T07:38:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"79485818286983047987991487256170936710","date":"2025-08-10T01:35:25+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-08-09T23:38:43+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-09T10:21:07+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-09T10:19:49+00:00","index":"","fulltext":""},{"type":"submitted","content":"Catalysis Surveys from Asia","date":"2025-08-08T21:09:32+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"catalysis-surveys-from-asia","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cats","sideBox":"Learn more about [Catalysis Surveys from Asia](http://link.springer.com/journal/10563)","snPcode":"10563","submissionUrl":"https://submission.nature.com/new-submission/10563/3","title":"Catalysis Surveys from Asia","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"d914ece9-e03b-4bde-89bd-693d0f914827","owner":[],"postedDate":"August 14th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-24T16:07:46+00:00","versionOfRecord":{"articleIdentity":"rs-7330203","link":"https://doi.org/10.1007/s10563-025-09468-z","journal":{"identity":"catalysis-surveys-from-asia","isVorOnly":false,"title":"Catalysis Surveys from Asia"},"publishedOn":"2025-11-19 15:58:53","publishedOnDateReadable":"November 19th, 2025"},"versionCreatedAt":"2025-08-14 06:41:47","video":"","vorDoi":"10.1007/s10563-025-09468-z","vorDoiUrl":"https://doi.org/10.1007/s10563-025-09468-z","workflowStages":[]},"version":"v1","identity":"rs-7330203","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7330203","identity":"rs-7330203","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}