{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T01:42:00Z","timestamp":1792806120030,"version":"4.5.0"},"reference-count":66,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2025,11,8]],"date-time":"2025-11-08T00:00:00Z","timestamp":1762560000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Fundamental Research Program of Shanxi Province","award":["202403021212041"],"award-info":[{"award-number":["202403021212041"]}]},{"name":"Scientific and Technological Innovation Fund Project of Shanxi Agricultural University","award":["2020BQ67"],"award-info":[{"award-number":["2020BQ67"]}],"id":[{"id":"https:\/\/ror.org\/05e9f5362","id-type":"ROR","asserted-by":"crossref"}]},{"name":"Scientific and Technological Innovation Fund Project of Shanxi Agricultural University","award":["2020BQ62"],"award-info":[{"award-number":["2020BQ62"]}],"id":[{"id":"https:\/\/ror.org\/05e9f5362","id-type":"ROR","asserted-by":"crossref"}]},{"name":"Scientific Research Project of Incentive Funds for Doctoral Graduates and Postdoctoral Researchers in Shanxi Province","award":["SXBYKY2021008"],"award-info":[{"award-number":["SXBYKY2021008"]}]},{"name":"Scientific Research Project of Incentive Funds for Doctoral Graduates and Postdoctoral Researchers in Shanxi Province","award":["SXBYKY2021009"],"award-info":[{"award-number":["SXBYKY2021009"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>In this study, two potassium-based alkaline compounds, KOH and K2CO3, were utilized as catalysts for the pyrolysis of bituminous coal to directly synthesize carbon nanotubes (CNTs). During the conventional reaction process, CNTs were observed as unusual products, with respective contents reaching 9.43 and 8.98 wt.% in the pyrolysis products. The results indicate that at temperatures exceeding 600 \u00b0C, KOH undergoes complete conversion into K2CO3. The melting point of K2CO3 (890 \u00b0C) serves as the critical temperature for the formation of CNTs. Under the reducing atmosphere provided by \u2013CH2\u2013 and aromatic C\u2013C structures in coal, the transformation process K2CO3 \u2192 K2O \u2192 K occurs. At high temperatures, highly etching K reacts with the C\u2013O\u2013C structures in coal, converting them into carbon atoms and exposing the iron (Fe)-containing minerals in coal to the particle surface. Finally, the carbon atoms derived from the ether bonds form CNTs under the action of the native Fe catalyst in coal. The resulting product is a mixture of activated carbon and CNTs. This method fundamentally alters the composition of traditional coal-based activated carbon and provides a new approach for the cost-effective, large-scale production of high-value CNTs.<\/jats:p>","DOI":"10.3390\/nano15221691","type":"journal-article","created":{"date-parts":[[2025,11,10]],"date-time":"2025-11-10T10:35:31Z","timestamp":1762770931000},"page":"1691","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Preparation and Formation Mechanism of Carbon Nanotubes via Coal Pyrolysis Using Alkaline Potassium Catalysts"],"prefix":"10.3390","volume":"15","author":[{"given":"Tiankai","family":"Zhang","sequence":"first","affiliation":[{"name":"Department of Basic Sciences, Shanxi Agricultural University, Taigu, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qi","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Basic Sciences, Shanxi Agricultural University, Taigu, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"140884","DOI":"10.1016\/j.conbuildmat.2025.140884","article-title":"Enhanced mechanical and thermal performance of high-strength engineered geopolymer composites reinforced by hybrid polyethylene fibres and carbon nanotubes","volume":"472","author":"Xie","year":"2025","journal-title":"Constr. 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