{"id":13274,"date":"2024-09-17T15:23:40","date_gmt":"2024-09-17T13:23:40","guid":{"rendered":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/?p=13274"},"modified":"2024-09-17T15:29:24","modified_gmt":"2024-09-17T13:29:24","slug":"thesis-defence-10","status":"publish","type":"post","link":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/2024\/09\/17\/thesis-defence-10\/","title":{"rendered":"Thesis defence"},"content":{"rendered":"<p>Title : <strong>\u00ab Mineral spirits: The redox transformations of<\/strong> <strong>CO<sub>2<\/sub> &amp; CH<sub>4<\/sub> mediated by Fe<sup>2+\/3+<\/sup> oxyhydroxide \u201cgreen rust\u201d minerals \u00bb<\/strong><\/p>\n<p><u>Composition du jury<\/u><\/p>\n<p><em>Rapporteurs<\/em><\/p>\n<p><strong>Laurent CHARLET<\/strong>, Professeur Em\u00e9rite, Universit\u00e9 de Grenoble Alpes<\/p>\n<p><strong>Abderrazak\u00a0EL ALBANI<\/strong>, Professeur, Universit\u00e9 de Poitiers<\/p>\n<p><em>Examinateurs<\/em><\/p>\n<p><strong>Anabella IVANCICH<\/strong>, Directrice de Recherche, CNRS<\/p>\n<p><strong>Christian RUBY<\/strong>, Professeur, Universit\u00e9 de Lorraine<\/p>\n<p><strong>Simon DUVAL,<\/strong> Membre invit\u00e9, Charg\u00e9 de recherche, CNRS<\/p>\n<p><strong>Michael J. RUSSELL<\/strong> Membre invit\u00e9, Professeur Em\u00e9rite, Universit\u00e9 de Turin<\/p>\n<p><em>Pr\u00e9sident du Jury<\/em><\/p>\n<p><strong>Fran\u00e7ois GUYOT<\/strong>, Professeur, Sorbonne Universit\u00e9<\/p>\n<p><em>Directeurs de th\u00e8se<\/em><\/p>\n<p><strong>Daniel FERRY<\/strong>\u00a0Directeur de th\u00e8se, Charg\u00e9 de recherche, CNRS<\/p>\n<p><strong>Wolfgang NITSCHKE<\/strong>\u00a0Co-encadrant de th\u00e8se, Directeur de recherche, CNRS<\/p>\n<p><strong>Abstract<\/strong> :<\/p>\n<p>Extant biological metabolism is powered by the efficient transfer of electrons between carbon species and coordinated metal atoms within specially evolved enzymes. However, this redox mechanism is not unique to biology as naturally occurring metals and mineral scaffolds conduct cryptic electron transfer throughout the environment. This abiotic redox cycling of carbon by minerals drove the geochemical evolution of marine and terrestrial environments prior to life, and it is implicated in its emergence. Structural homology between the lattice coordination of certain reactive minerals and enzymatic reaction centers suggests a geochemical transition between abiotic and biological chemical systems. This thesis explores this hypothesis and identifies the unique layered nanomineral Fe<sup>2+\/<\/sup>Fe<sup>3+<\/sup> oxyhydroxide \u2018green rust\u2019 as a potential candidate for this transition due to its impressive electron transfer and versatile ionic exchange properties. We experimentally demonstrate the novel redox chemistry of Fe-oxyhydroxide green rust (GR) minerals towards CO<sub>2<\/sub> and CH<sub>4\u00a0<\/sub>gases under a barrage of conditions (e.g. pressure, temperature, UV irradiation) and characterize the reactions via spectroscopic and spectrometric analysis (e.g. XRD, Raman, FTIR, XPS, NMR, and GC-MS). We identify various products formed from the reduction of CO<sub>2<\/sub> and oxidation of CH<sub>4<\/sub> mediated by Fe-oxyhydroxide GR, supporting the hypothesis that life emerged from reactive minerals that mediate complex organic chemistry pathways mimicking extant carbon fixation metabolisms. Additionally, certain products formed by GR mediated carbon redox have strong implications over early climate forcing and the nature of the abiotic controls over the development of the biosphere.<\/p>\n<p><em><u>Key words<\/u><\/em> : redox, iron oxyhydroxide, green rust, reactive mineral, methane oxidation, carbon dioxide reduction, climate, origin of life<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Orion Farr will speak on September 25 at 14H00 in the  &#8220;amphith\u00e9\u00e2tre P. Desnuelle&#8221; (Campus Joseph Aiguier)<\/p>\n","protected":false},"author":16,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[5],"tags":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/wp-json\/wp\/v2\/posts\/13274"}],"collection":[{"href":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/wp-json\/wp\/v2\/comments?post=13274"}],"version-history":[{"count":1,"href":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/wp-json\/wp\/v2\/posts\/13274\/revisions"}],"predecessor-version":[{"id":13275,"href":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/wp-json\/wp\/v2\/posts\/13274\/revisions\/13275"}],"wp:attachment":[{"href":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/wp-json\/wp\/v2\/media?parent=13274"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/wp-json\/wp\/v2\/categories?post=13274"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cinam.univ-mrs.fr\/cinam\/en\/wp-json\/wp\/v2\/tags?post=13274"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}