{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T03:52:59Z","timestamp":1780631579291,"version":"3.54.1"},"reference-count":24,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2024,12,1]],"date-time":"2024-12-01T00:00:00Z","timestamp":1733011200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004329","name":"Slovenian Research Agency","doi-asserted-by":"publisher","award":["P2-0152"],"award-info":[{"award-number":["P2-0152"]}],"id":[{"id":"10.13039\/501100004329","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004329","name":"Slovenian Research Agency","doi-asserted-by":"publisher","award":["J2-1723"],"award-info":[{"award-number":["J2-1723"]}],"id":[{"id":"10.13039\/501100004329","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004329","name":"Slovenian Research Agency","doi-asserted-by":"publisher","award":["J2-2492"],"award-info":[{"award-number":["J2-2492"]}],"id":[{"id":"10.13039\/501100004329","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Combining carboxylation reactions using carbon dioxide (CO2) as a reactant with phenol results in creation of new C-C bonds, and represents one of the most promising routes in sustainable utilization of ubiquitous and readily available resources for production of highly valuable products. This study provides a detailed and well-structured investigation of the effect of various reaction conditions (reactant loading, reaction duration, temperature, CO2 pressure) on the carboxylation of phenol. Sodium phenoxide carboxylation showed well-resolved trends with variation of temperature and time, and resulted in production of salicylic acid (SA) in the range of 11.4 to 47.8%, 4-hydoxybenzoic acid (4HBA) in the range of 2.0 to 8.2%, while the dicarboxylated 4-hydroxyisophthalic acid (4HiPh) was only detected in trace amounts. The effect of the variation of reactant content was shown to be significantly influenced by the reactor size, solid\/vessel and gas\/solid contact area, as well as the efficiency of the stirring. CO2 pressure was shown to be a crucial element, where reactions carried out below 2 MPa CO2 did not show any activity. While investigating the reaction mechanism, it was shown that the salt analogues of potential products could be acidified in situ by the moisture present, and immediately degraded back to phenol, thus lowering yields of potentially obtained products. The experimental results were successfully used to compose a kinetic model, which very well describes the experimentally obtained results. As such, this study provides a valuable dataset for valorization of lignocellulosic aromatic compounds as well as highly abundant and environmentally detrimental carbon dioxide into industrially valuable mono- and dicarboxylic acids.<\/jats:p>","DOI":"10.3390\/ijms252312923","type":"journal-article","created":{"date-parts":[[2024,12,2]],"date-time":"2024-12-02T05:43:43Z","timestamp":1733118223000},"page":"12923","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Mechanism, Kinetics and Modelling of Phenol Carboxylation Reactions with CO2"],"prefix":"10.3390","volume":"25","author":[{"given":"Aleksa","family":"Koj\u010dinovi\u0107","sequence":"first","affiliation":[{"name":"Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia"},{"name":"Graduate School, University of Nova Gorica, Vipavska Cesta 13, 5000 Nova Gorica, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7226-4302","authenticated-orcid":false,"given":"Bla\u017e","family":"Likozar","sequence":"additional","affiliation":[{"name":"Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia"},{"name":"Pulp and Paper Institute, Bogi\u0161i\u0107eva 8, 1000 Ljubljana, Slovenia"},{"name":"Faculty of Polymer Technology, Ozare 19, SI-2380 Slovenj Gradec, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8255-647X","authenticated-orcid":false,"given":"Miha","family":"Grilc","sequence":"additional","affiliation":[{"name":"Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia"},{"name":"Graduate School, University of Nova Gorica, Vipavska Cesta 13, 5000 Nova Gorica, Slovenia"},{"name":"Pulp and Paper Institute, Bogi\u0161i\u0107eva 8, 1000 Ljubljana, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"15948","DOI":"10.1002\/anie.201803186","article-title":"Transition-Metal-Catalyzed Carboxylation Reactions with Carbon Dioxide","volume":"57","author":"Tortajada","year":"2018","journal-title":"Angew. Chemie Int. Ed."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Zhang, R., Ke, Q., Zhang, Z., Zhou, B., Cui, G., and Lu, H. (2022). Tuning Functionalized Ionic Liquids for CO2 Capture. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms231911401"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Kojcinovic, A., Likozar, B., and Grilc, M. (2022). Heterogeneous Catalytic Materials for Carboxylation Reactions with CO2 as Reactant. J. CO2 Util., 66.","DOI":"10.1016\/j.jcou.2022.102250"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"17475","DOI":"10.1021\/acssuschemeng.0c06099","article-title":"Acid-Catalyzed \u03b1-O-4 Aryl-Ether Cleavage Mechanisms in (Aqueous) \u03b3-Valerolactone: Catalytic Depolymerization Reactions of Lignin Model Compound during Organosolv Pretreatment","volume":"8","author":"Grilc","year":"2020","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2563","DOI":"10.1021\/acssuschemeng.3c05541","article-title":"Economic and Environmental Trade-Offs of Simultaneous Sugar and Lignin Utilization for Biobased Fuels and Chemicals","volume":"12","author":"Baral","year":"2024","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3317","DOI":"10.1002\/cssc.201701058","article-title":"C\u2212H Carboxylation of Aromatic Compounds through CO2 Fixation","volume":"10","author":"Luo","year":"2017","journal-title":"ChemSusChem"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"7488","DOI":"10.1039\/D1GC02158C","article-title":"Production of Active Pharmaceutical Ingredients (APIs) from Lignin-Derived Phenol and Catechol","volume":"23","author":"Park","year":"2021","journal-title":"Green Chem."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Naz, S., Bilal, A., Saddiq, B., Ejaz, S., Ali, S., Ain Haider, S.T., Sardar, H., Nasir, B., Ahmad, I., and Tiwari, R.K. (2022). Foliar Application of Salicylic Acid Improved Growth, Yield, Quality and Photosynthesis of Pea (Pisum sativum L.) by Improving Antioxidant Defense Mechanism under Saline Conditions. Sustainability, 14.","DOI":"10.3390\/su142114180"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1002\/jlac.18601150207","article-title":"Ueber Die Constitution Und Basicit\u00e4t Der Salicyls\u00e4ure","volume":"115","author":"Kolbe","year":"1860","journal-title":"Justus Liebigs Ann. Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1021\/cr50016a001","article-title":"The Kolbe-Schmitt Reaction","volume":"57","author":"Lindsey","year":"1957","journal-title":"Chem. Rev."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Koj\u010dinovi\u0107, A., Likozar, B., and Grilc, M. (2023). Sustainable CO 2 Fixation onto Bio-Based Aromatics. Sustainability, 15.","DOI":"10.3390\/su152316321"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1021\/jo01148a002","article-title":"The Kolbe-Schmitt Reaction. I. Variations in the Carbonation of p-Cresol","volume":"15","author":"Cameron","year":"1950","journal-title":"J. Org. Chem."},{"key":"ref_13","first-page":"812","article-title":"Theoretical Study of the Kolbe-Schmitt Reaction Mechanism","volume":"57","author":"Engelbrecht","year":"2002","journal-title":"Z. Naturforsch. Sect. A J. Phys. Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1957","DOI":"10.1021\/ci0600556","article-title":"Influence of Alkali Metal Cations upon the Kolbe-Schmitt Reaction Mechanism","volume":"46","author":"Markovic","year":"2006","journal-title":"J. Chem. Inf. Model."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"619","DOI":"10.1246\/bcsj.75.619","article-title":"Effects of Alkali and Alkaline Earth Metals on the Kolbe-Schmitt Reaction","volume":"75","author":"Rahim","year":"2002","journal-title":"Bull. Chem. Soc. Jpn."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1754","DOI":"10.1039\/C8GC00008E","article-title":"Pressurized CO2 as a Carboxylating Agent for the Biocatalytic: Ortho -Carboxylation of Resorcinol","volume":"20","author":"Plasch","year":"2018","journal-title":"Green Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"9837","DOI":"10.1039\/C9CC04550C","article-title":"Kolbe-Schmitt Type Reaction under Ambient Conditions Mediated by an Organic Base","volume":"55","author":"Sadamitsu","year":"2019","journal-title":"Chem. Commun."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"510","DOI":"10.1021\/jo01369a006","article-title":"A Study of the Kolbe-Schmitt Reaction. II. The Carbonation of Phenols","volume":"19","author":"Baine","year":"1954","journal-title":"J. Org. Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"6798","DOI":"10.1002\/chem.201601114","article-title":"Carboxylation of Phenols with CO2 at Atmospheric Pressure","volume":"22","author":"Luo","year":"2016","journal-title":"Chem. A Eur. J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5309","DOI":"10.1016\/j.tetlet.2007.05.132","article-title":"The Improved Kolbe-Schmitt Reaction Using Supercritical Carbon Dioxide","volume":"48","author":"Iijima","year":"2007","journal-title":"Tetrahedron Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.molstruc.2016.03.005","article-title":"DFT Computational Study on Decarboxylation Mechanism of Salicylic Acid and Its Derivatives in the Anionic State","volume":"1116","author":"Gao","year":"2016","journal-title":"J. Mol. Struct."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1392","DOI":"10.1134\/S0036024407090087","article-title":"Mechanism of the Kolbe-Schmitt Reaction with Lithium and Sodium Phenoxides","volume":"81","year":"2007","journal-title":"Russ. J. Phys. Chem. A"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"487","DOI":"10.1016\/S0167-2991(98)80802-1","article-title":"Carboxylation Reaction with Carbon Dioxide. Mechanistic Studies on the Kolbe-Schmitt Reaction","volume":"114","author":"Kosugi","year":"1998","journal-title":"Stud. Surf. Sci. Catal."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Hunt, S.E., Idris Jones, J., Lindsey, A.S., Killoh, D.C., and Turner, H.S. (1958). 639. Mechanism of the Kolbe\u2013Schmitt reaction. Part II. Influence of the alkali metal. J. Chem. 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