{"id":{"repo_id":"south-carolina","oai_identifier":"oai:scholarcommons.sc.edu:etd-1575"},"canonical_url":"https://search.dev.ndltd.org/etd/south-carolina/oai:scholarcommons.sc.edu:etd-1575","repository":{"repo_id":"south-carolina","name":"University of South Carolina","base_url":"https://scholarcommons.sc.edu/do/oai/"},"display":{"title":"Bimetallic Electrocatalysts on TiO2 -Based Supports for Methanol Oxidation and Oxygen Evolution","abstract":"<p>Electrocatalysts are essential for the development of active and durable fuel cells and hydrogen production technologies. Generally, electrochemical processes of energy conversion and hydrogen generation in a Proton Exchange Membrane (PEM) utilize precious metals, such as platinum, iridium and ruthenium, as electrocatalysts. For the methanol oxidation and oxygen evolution reaction, a bimetallic structure can be used to enhance kinetics and increase stability. It is desired to support electrocatalysts to disperse nanoparticles on the surface and promote better catalyst utilization. Traditionally, carbon has been used as an electrochemical support because it has a high surface area and high electrical conductivity. The problem with carbon is that it is not a very stable material and can corrode at voltages more than 0.9 V, affecting performance of the electrochemical reaction. Therefore, it would be useful to support electrocatalysts in a stable material with suitable conductivity</p> <p>Using titanium dioxide as a support can be advantageous due to its corrosion-resistant capability. TiO<sub>2</sub> exhibit different crystalline structures, such as anatase and rutile, which can have an effect on catalytic activity. Unfortunately, it is not conductive; hence, it is not used in electrochemical applications. However, it can be doped with niobium to increase electronic conductivity; but, it usually come at the expense of surface area. In this work, TiO<sub>2</sub> and Nb-TiO<sub>2</sub> were studied as platinum/ruthenium and iridium/ruthenium nanoparticles supports for the electrochemical oxidation of methanol and oxygen evolution, respectively. Even though the conductivity of our supports was very low, adding a considerable loading of nanoparticles increased conductivity of the composite material (support + catalyst) to acceptable levels. Using cyclic voltammetry (CV) and direct methanol fuel cell tests creating a membrane electrode assembly (MEA), Pt-Ru supported on Nb-TiO<sub>2</sub> and TiO<sub>2</sub> showed superior activity over similar catalysts supported on carbon. Also, the supported electrocatalysts on anatase TiO<sub>2</sub> were more active than supported on rutile for methanol electrooxidation. For the case of oxygen evolution reaction (OER), supported Ir:Ru nanoparticles had higher performance than unsupported metal and corresponding metal oxide. It is known that metal oxides are more durable than bare metals for OER. Performing durability studies in CV it was demonstrated that even the metal oxide Ir<sub>0.5</sub>Ru<sub>0.5</sub>O<sub>2</sub> can degrade. However, when titanium was added to this metal oxide, the stability improved. Polarization experiments in a PEM water electrolyzer were tested for Ir<sub>0.45</sub>Ru<sub>0.45</sub>Ti<sub>0.10</sub>O<sub>2</sub>; and it was found a higher performance at current densities more than 1 A/cm<super>2</super>, compared to the Ir:Ru supported nanoparticles.</p>","abstract_html":"&lt;p&gt;Electrocatalysts are essential for the development of active and durable fuel cells and hydrogen production technologies. Generally, electrochemical processes of energy conversion and hydrogen generation in a Proton Exchange Membrane (PEM) utilize precious metals, such as platinum, iridium and ruthenium, as electrocatalysts. For the methanol oxidation and oxygen evolution reaction, a bimetallic structure can be used to enhance kinetics and increase stability. It is desired to support electrocatalysts to disperse nanoparticles on the surface and promote better catalyst utilization. Traditionally, carbon has been used as an electrochemical support because it has a high surface area and high electrical conductivity. The problem with carbon is that it is not a very stable material and can corrode at voltages more than 0.9 V, affecting performance of the electrochemical reaction. Therefore, it would be useful to support electrocatalysts in a stable material with suitable conductivity&lt;/p&gt; &lt;p&gt;Using titanium dioxide as a support can be advantageous due to its corrosion-resistant capability. TiO&lt;sub&gt;2&lt;/sub&gt; exhibit different crystalline structures, such as anatase and rutile, which can have an effect on catalytic activity. Unfortunately, it is not conductive; hence, it is not used in electrochemical applications. However, it can be doped with niobium to increase electronic conductivity; but, it usually come at the expense of surface area. In this work, TiO&lt;sub&gt;2&lt;/sub&gt; and Nb-TiO&lt;sub&gt;2&lt;/sub&gt; were studied as platinum/ruthenium and iridium/ruthenium nanoparticles supports for the electrochemical oxidation of methanol and oxygen evolution, respectively. Even though the conductivity of our supports was very low, adding a considerable loading of nanoparticles increased conductivity of the composite material (support + catalyst) to acceptable levels. Using cyclic voltammetry (CV) and direct methanol fuel cell tests creating a membrane electrode assembly (MEA), Pt-Ru supported on Nb-TiO&lt;sub&gt;2&lt;/sub&gt; and TiO&lt;sub&gt;2&lt;/sub&gt; showed superior activity over similar catalysts supported on carbon. Also, the supported electrocatalysts on anatase TiO&lt;sub&gt;2&lt;/sub&gt; were more active than supported on rutile for methanol electrooxidation. For the case of oxygen evolution reaction (OER), supported Ir:Ru nanoparticles had higher performance than unsupported metal and corresponding metal oxide. It is known that metal oxides are more durable than bare metals for OER. Performing durability studies in CV it was demonstrated that even the metal oxide Ir&lt;sub&gt;0.5&lt;/sub&gt;Ru&lt;sub&gt;0.5&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; can degrade. However, when titanium was added to this metal oxide, the stability improved. Polarization experiments in a PEM water electrolyzer were tested for Ir&lt;sub&gt;0.45&lt;/sub&gt;Ru&lt;sub&gt;0.45&lt;/sub&gt;Ti&lt;sub&gt;0.10&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;; and it was found a higher performance at current densities more than 1 A/cm&lt;super&gt;2&lt;/super&gt;, compared to the Ir:Ru supported nanoparticles.&lt;/p&gt;","abstract_has_math":false,"creators":["Fuentes, Roderick Eliel"],"institution":null,"degree_name":"Ph.D.","degree_level":"Campus Access Dissertation","degree_discipline":"Chemical Engineering","degree_department":null,"school":null,"contributors":["John W Weidner"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-01-01T08:00:00Z","date_published":"2011-01-01T08:00:00Z","updated_at":"2026-07-24T04:37:49Z","subjects":["Chemical Engineering","Engineering","electrocatalysis","methanol oxidation","oxigen evolution","titanium dioxide"],"languages":[],"rights":["© 2011, Roderick Eliel Fuentes"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarcommons.sc.edu/etd/574","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["John W Weidner"]},{"key":"dc:creator","label":"Author","values":["Fuentes, Roderick Eliel"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Campus Access Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Chemical Engineering","Engineering","electrocatalysis","methanol oxidation","oxigen evolution","titanium dioxide"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["© 2011, Roderick Eliel Fuentes"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarcommons.sc.edu/etd/574"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["<p>Electrocatalysts are essential for the development of active and durable fuel cells and hydrogen production technologies. Generally, electrochemical processes of energy conversion and hydrogen generation in a Proton Exchange Membrane (PEM) utilize precious metals, such as platinum, iridium and ruthenium, as electrocatalysts. For the methanol oxidation and oxygen evolution reaction, a bimetallic structure can be used to enhance kinetics and increase stability. It is desired to support electrocatalysts to disperse nanoparticles on the surface and promote better catalyst utilization. Traditionally, carbon has been used as an electrochemical support because it has a high surface area and high electrical conductivity. The problem with carbon is that it is not a very stable material and can corrode at voltages more than 0.9 V, affecting performance of the electrochemical reaction. Therefore, it would be useful to support electrocatalysts in a stable material with suitable conductivity</p> <p>Using titanium dioxide as a support can be advantageous due to its corrosion-resistant capability. TiO<sub>2</sub> exhibit different crystalline structures, such as anatase and rutile, which can have an effect on catalytic activity. Unfortunately, it is not conductive; hence, it is not used in electrochemical applications. However, it can be doped with niobium to increase electronic conductivity; but, it usually come at the expense of surface area. In this work, TiO<sub>2</sub> and Nb-TiO<sub>2</sub> were studied as platinum/ruthenium and iridium/ruthenium nanoparticles supports for the electrochemical oxidation of methanol and oxygen evolution, respectively. Even though the conductivity of our supports was very low, adding a considerable loading of nanoparticles increased conductivity of the composite material (support + catalyst) to acceptable levels. Using cyclic voltammetry (CV) and direct methanol fuel cell tests creating a membrane electrode assembly (MEA), Pt-Ru supported on Nb-TiO<sub>2</sub> and TiO<sub>2</sub> showed superior activity over similar catalysts supported on carbon. Also, the supported electrocatalysts on anatase TiO<sub>2</sub> were more active than supported on rutile for methanol electrooxidation. For the case of oxygen evolution reaction (OER), supported Ir:Ru nanoparticles had higher performance than unsupported metal and corresponding metal oxide. It is known that metal oxides are more durable than bare metals for OER. Performing durability studies in CV it was demonstrated that even the metal oxide Ir<sub>0.5</sub>Ru<sub>0.5</sub>O<sub>2</sub> can degrade. However, when titanium was added to this metal oxide, the stability improved. Polarization experiments in a PEM water electrolyzer were tested for Ir<sub>0.45</sub>Ru<sub>0.45</sub>Ti<sub>0.10</sub>O<sub>2</sub>; and it was found a higher performance at current densities more than 1 A/cm<super>2</super>, compared to the Ir:Ru supported nanoparticles.</p>"]},{"key":"dc:title","label":"Title","values":["Bimetallic Electrocatalysts on TiO2 -Based Supports for Methanol Oxidation and Oxygen Evolution"]}]}],"canonical_facts":{"dc:contributor":["John W Weidner"],"dc:creator":["Fuentes, Roderick Eliel"],"dc:description.abstract":["<p>Electrocatalysts are essential for the development of active and durable fuel cells and hydrogen production technologies. Generally, electrochemical processes of energy conversion and hydrogen generation in a Proton Exchange Membrane (PEM) utilize precious metals, such as platinum, iridium and ruthenium, as electrocatalysts. For the methanol oxidation and oxygen evolution reaction, a bimetallic structure can be used to enhance kinetics and increase stability. It is desired to support electrocatalysts to disperse nanoparticles on the surface and promote better catalyst utilization. Traditionally, carbon has been used as an electrochemical support because it has a high surface area and high electrical conductivity. The problem with carbon is that it is not a very stable material and can corrode at voltages more than 0.9 V, affecting performance of the electrochemical reaction. Therefore, it would be useful to support electrocatalysts in a stable material with suitable conductivity</p> <p>Using titanium dioxide as a support can be advantageous due to its corrosion-resistant capability. TiO<sub>2</sub> exhibit different crystalline structures, such as anatase and rutile, which can have an effect on catalytic activity. Unfortunately, it is not conductive; hence, it is not used in electrochemical applications. However, it can be doped with niobium to increase electronic conductivity; but, it usually come at the expense of surface area. In this work, TiO<sub>2</sub> and Nb-TiO<sub>2</sub> were studied as platinum/ruthenium and iridium/ruthenium nanoparticles supports for the electrochemical oxidation of methanol and oxygen evolution, respectively. Even though the conductivity of our supports was very low, adding a considerable loading of nanoparticles increased conductivity of the composite material (support + catalyst) to acceptable levels. Using cyclic voltammetry (CV) and direct methanol fuel cell tests creating a membrane electrode assembly (MEA), Pt-Ru supported on Nb-TiO<sub>2</sub> and TiO<sub>2</sub> showed superior activity over similar catalysts supported on carbon. Also, the supported electrocatalysts on anatase TiO<sub>2</sub> were more active than supported on rutile for methanol electrooxidation. For the case of oxygen evolution reaction (OER), supported Ir:Ru nanoparticles had higher performance than unsupported metal and corresponding metal oxide. It is known that metal oxides are more durable than bare metals for OER. Performing durability studies in CV it was demonstrated that even the metal oxide Ir<sub>0.5</sub>Ru<sub>0.5</sub>O<sub>2</sub> can degrade. However, when titanium was added to this metal oxide, the stability improved. Polarization experiments in a PEM water electrolyzer were tested for Ir<sub>0.45</sub>Ru<sub>0.45</sub>Ti<sub>0.10</sub>O<sub>2</sub>; and it was found a higher performance at current densities more than 1 A/cm<super>2</super>, compared to the Ir:Ru supported nanoparticles.</p>"],"dc:identifier":["https://scholarcommons.sc.edu/etd/574"],"dc:rights":["© 2011, Roderick Eliel Fuentes"],"dc:subject":["Chemical Engineering","Engineering","electrocatalysis","methanol oxidation","oxigen evolution","titanium dioxide"],"dc:title":["Bimetallic Electrocatalysts on TiO2 -Based Supports for Methanol Oxidation and Oxygen Evolution"],"thesis:degree_discipline":["Chemical Engineering"],"thesis:degree_level":["Campus Access Dissertation"],"thesis:degree_name":["Ph.D."]},"updated_at":"2026-07-24T04:37:49Z"}