{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/44211"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/44211","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"The influence of inert anode material and electrolyte composition on the electrochemical production of oxygen from molten oxides","abstract":"Shifts in global and political climates have led industries worldwide to search for more environmentally sound processes that are still economically viable. The steel industry is studying the feasibility of molten oxide electrolysis, a novel process by which molten iron and gaseous oxygen are the products; no carbon dioxide is produced at the site of the electrolysis cell. The research presented in this thesis focuses on the anodic reaction and the preliminary development of an inert anode, as well as investigations into the mechanism of the oxygen evolution reaction. Various elements have been considered with the platinum group metals possessing the best combination of physical properties to serve as the inert anode. Cyclic voltammetry at 1575°C was used to compare the candidates. Iridium yielded the highest current density at a given overpotential followed by rhodium and platinum regardless of the composition of the electrolyte. Speculation as to metal oxide intermediate phases formed and mechanisms for the oxygen evolution reaction are discussed. Notably, the basicity of the molten aluminosilicate electrolyte was found to greatly influence the rate of oxygen gas evolution as evidenced by the linear dependence of the current density on optical basicity. This is crucial for the design of a full-scale electrolysis cell as improved kinetics of the anodic reaction will yield higher throughput and/or enhanced power efficiency. Combining our finding of the relationship between current density and basicity with previous authors' contributions on the effect of partial pressure of oxygen, we argue that to a first approximation, the magnitude of the current density is governed by the concentration of free oxide ions and by the partial pressure of oxygen in the headspace above the melt.","abstract_html":"Shifts in global and political climates have led industries worldwide to search for more environmentally sound processes that are still economically viable. The steel industry is studying the feasibility of molten oxide electrolysis, a novel process by which molten iron and gaseous oxygen are the products; no carbon dioxide is produced at the site of the electrolysis cell. The research presented in this thesis focuses on the anodic reaction and the preliminary development of an inert anode, as well as investigations into the mechanism of the oxygen evolution reaction. Various elements have been considered with the platinum group metals possessing the best combination of physical properties to serve as the inert anode. Cyclic voltammetry at 1575°C was used to compare the candidates. Iridium yielded the highest current density at a given overpotential followed by rhodium and platinum regardless of the composition of the electrolyte. Speculation as to metal oxide intermediate phases formed and mechanisms for the oxygen evolution reaction are discussed. Notably, the basicity of the molten aluminosilicate electrolyte was found to greatly influence the rate of oxygen gas evolution as evidenced by the linear dependence of the current density on optical basicity. This is crucial for the design of a full-scale electrolysis cell as improved kinetics of the anodic reaction will yield higher throughput and/or enhanced power efficiency. Combining our finding of the relationship between current density and basicity with previous authors' contributions on the effect of partial pressure of oxygen, we argue that to a first approximation, the magnitude of the current density is governed by the concentration of free oxide ions and by the partial pressure of oxygen in the headspace above the melt.","abstract_has_math":false,"creators":["Gmitter, Andrew J"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.","school":null,"contributors":[],"advisors":["Donald R. Sadoway."],"committee_chairs":[],"committee_members":[],"year":2008,"date_issued":"2008","date_published":"2008","updated_at":"2026-07-22T22:21:18Z","subjects":["Materials Science and Engineering."],"languages":["eng"],"rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"rights_urls":["http://dspace.mit.edu/handle/1721.1/7582"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1721.1/44211","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Donald R. Sadoway."]},{"key":"dc:contributor.department","label":"Department","values":["Massachusetts Institute of Technology. Dept. of Materials Science and Engineering."]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["Massachusetts Institute of Technology. Dept. of Materials Science and Engineering."]},{"key":"dc:creator","label":"Author","values":["Gmitter, Andrew J"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2009-01-26T22:01:56Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2009-01-26T22:01:56Z"]},{"key":"dc:date.issued","label":"Date","values":["2008"]},{"key":"dc:publisher","label":"Institution","values":["Massachusetts Institute of Technology"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Materials Science and Engineering."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://dspace.mit.edu/handle/1721.1/7582"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1721.1/44211"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008.","This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.","Includes bibliographical references (p. 109-116)."]},{"key":"dc:description.abstract","label":"Abstract","values":["Shifts in global and political climates have led industries worldwide to search for more environmentally sound processes that are still economically viable. The steel industry is studying the feasibility of molten oxide electrolysis, a novel process by which molten iron and gaseous oxygen are the products; no carbon dioxide is produced at the site of the electrolysis cell. The research presented in this thesis focuses on the anodic reaction and the preliminary development of an inert anode, as well as investigations into the mechanism of the oxygen evolution reaction. Various elements have been considered with the platinum group metals possessing the best combination of physical properties to serve as the inert anode. Cyclic voltammetry at 1575°C was used to compare the candidates. Iridium yielded the highest current density at a given overpotential followed by rhodium and platinum regardless of the composition of the electrolyte. Speculation as to metal oxide intermediate phases formed and mechanisms for the oxygen evolution reaction are discussed. Notably, the basicity of the molten aluminosilicate electrolyte was found to greatly influence the rate of oxygen gas evolution as evidenced by the linear dependence of the current density on optical basicity. This is crucial for the design of a full-scale electrolysis cell as improved kinetics of the anodic reaction will yield higher throughput and/or enhanced power efficiency. Combining our finding of the relationship between current density and basicity with previous authors' contributions on the effect of partial pressure of oxygen, we argue that to a first approximation, the magnitude of the current density is governed by the concentration of free oxide ions and by the partial pressure of oxygen in the headspace above the melt.","(cont.) Lastly, to, in part, address the disparate natures of the interests of steelmakers, glassmakers, geochemists, and electrochemists, the difficulties in performing electrochemical measurements at extremely high temperatures (~1600°C), and the absence of a comprehensive review of the last sixty years of work on oxygen evolution from molten silicates, this thesis is intended to serve as an essential guide for future work in this field."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["S.M."]},{"key":"dc:title","label":"Title","values":["The influence of inert anode material and electrolyte composition on the electrochemical production of oxygen from molten oxides"]}]}],"canonical_facts":{"dc:contributor.advisor":["Donald R. Sadoway."],"dc:contributor.department":["Massachusetts Institute of Technology. Dept. of Materials Science and Engineering."],"dc:contributor.other":["Massachusetts Institute of Technology. Dept. of Materials Science and Engineering."],"dc:creator":["Gmitter, Andrew J"],"dc:date.accessioned":["2009-01-26T22:01:56Z"],"dc:date.available":["2009-01-26T22:01:56Z"],"dc:date.issued":["2008"],"dc:description":["Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008.","This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.","Includes bibliographical references (p. 109-116)."],"dc:description.abstract":["Shifts in global and political climates have led industries worldwide to search for more environmentally sound processes that are still economically viable. The steel industry is studying the feasibility of molten oxide electrolysis, a novel process by which molten iron and gaseous oxygen are the products; no carbon dioxide is produced at the site of the electrolysis cell. The research presented in this thesis focuses on the anodic reaction and the preliminary development of an inert anode, as well as investigations into the mechanism of the oxygen evolution reaction. Various elements have been considered with the platinum group metals possessing the best combination of physical properties to serve as the inert anode. Cyclic voltammetry at 1575°C was used to compare the candidates. Iridium yielded the highest current density at a given overpotential followed by rhodium and platinum regardless of the composition of the electrolyte. Speculation as to metal oxide intermediate phases formed and mechanisms for the oxygen evolution reaction are discussed. Notably, the basicity of the molten aluminosilicate electrolyte was found to greatly influence the rate of oxygen gas evolution as evidenced by the linear dependence of the current density on optical basicity. This is crucial for the design of a full-scale electrolysis cell as improved kinetics of the anodic reaction will yield higher throughput and/or enhanced power efficiency. Combining our finding of the relationship between current density and basicity with previous authors' contributions on the effect of partial pressure of oxygen, we argue that to a first approximation, the magnitude of the current density is governed by the concentration of free oxide ions and by the partial pressure of oxygen in the headspace above the melt.","(cont.) Lastly, to, in part, address the disparate natures of the interests of steelmakers, glassmakers, geochemists, and electrochemists, the difficulties in performing electrochemical measurements at extremely high temperatures (~1600°C), and the absence of a comprehensive review of the last sixty years of work on oxygen evolution from molten silicates, this thesis is intended to serve as an essential guide for future work in this field."],"dc:description.degree":["S.M."],"dc:identifier.uri":["http://hdl.handle.net/1721.1/44211"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"dc:rights.uri":["http://dspace.mit.edu/handle/1721.1/7582"],"dc:subject":["Materials Science and Engineering."],"dc:title":["The influence of inert anode material and electrolyte composition on the electrochemical production of oxygen from molten oxides"],"dc:type":["Thesis"]},"updated_at":"2026-07-22T22:21:18Z"}