Person: Cascos Jiménez, Vanessa Amelia
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First Name
Vanessa Amelia
Last Name
Cascos Jiménez
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Inorgánica
Area
Identifiers
8 results
Search Results
Now showing 1 - 8 of 8
Item SrCo0.50Fe0.40Ir0.10O3−δ decorated with Pd and La0.8Sr0.2Ga0.83Mg0.17O3−δ: a cleaner electrode for intermediate-temperature solid oxide fuel cells with reduced cobalt content(ACS Applied Energy Materials, 2024) Chivite-Lacaba, Mónica; Prado Gonjal, Jesús De La Paz; Troncoso, Loreto; Cascos Jiménez, Vanessa AmeliaRecent studies related to cathode materials for solid oxide fuel cells (SOFCs) have showcased the feasibility of stabilizing cubic or tetragonal perovskite phases in the SrCoO3−δ system at room temperature. This achievement has been facilitated by partially substituting Co atoms with small amounts of highly charged cations such as Ir4+ in SrCo0.90Ir0.10O3−δ. This specific material exhibits exceptional performance as a cathode for SOFCs operating at intermediate temperatures (800−850 °C). However, it contains a high amount of cobalt, which is both costly and toxic. In this study, our focus has been on further improving this material by reducing its cobalt content, resulting in a cleaner and more cost-effective cathode for SOFCs. The resulting SrCo0.50Fe0.40Ir0.10O3−δ perovskite, synthesized by the citrate method, introduces a 40% composition of Fe in the sites of Co and Ir, effectively decreasing the amount of Co in the material. The crystal structure of this perovskite oxide has been analyzed using X-ray diffraction (XRD) and neutron powder diffraction (NPD), allowing us to establish correlations with its mechanical and electrical properties. In the single-cell test, this material gave reasonable performances as a cathode at intermediate temperatures (800−850 °C), with La0.8Sr0.2Ga0.83Mg0.17O3−δ (LSGM) as the electrolyte. An analysis of the chemical compatibility between the cathode and the electrolyte, LSGM, demonstrated no interaction at elevated temperatures. Thermal expansion coefficient (TEC) measurements exhibited consistent linear expansion across the entire temperature range. Lastly, the perovskite displayed commendable electrical conductivity along with a promising power density measurement of 384 mW/cm2 at 850 °C. These findings collectively suggest the potential of this material as a viable cleaner cathode option for intermediate-temperature SOFCs. Moreover, the cathode was further optimized and the performance of the cell improved, by either infiltrating SrCo0.50Fe0.40Ir0.10O3−δ with a Pd(NO3)2 solution or mixing it with 30% of LSGM electrolyte, resulting in higher power densities (568 and 675 mW/cm2, respectively) in test cells fed with pure H2 as a fuel.- Project number: PIMCD95/23-24
Item Modelos bidimensionales y tridimensionales para la enseñanza de la Cristalografía y la Mineralogía(2024) Pina Martínez, Carlos Manuel; Ávila Brande, David; Cabeza Llorca, Ana; Cascos Jiménez, Vanessa Amelia; Crespo López, Ángel; Fernández Sequeira, Vinicio; González Illanes, Tamara; López-Acevedo Cornejo, María Victoria; Pallarés Zazo, Ana; Prado Gonjal, Jesús De La Paz; Solana Madruga, Elena; Pimentel Guerra, Carlos; Pina Martínez, Carlos Manuel Item Microwave-assisted synthesis of thermoelectric oxides and chalcogenides(Ceramics International, 2022) González-Barrios, Marta María; Tabuyo Martínez, Marina; Cascos Jiménez, Vanessa Amelia; Durá, Óscar Juan; Alonso, José Antonio; Ávila Brande, David; Prado Gonjal, Jesús De La PazThe combination of microwaves with other classical synthetic methods may be considered as a powerful tool for the preparation of metal oxides and metal chalcogenides. This approach allows the modification of the reaction kinetic significantly by shortening the processing time to minutes and it minimizes the energy consumption during the synthesis. In this work, potential thermoelectric compounds, which enable the direct conversion of temperature gradients into useful electric energy, have been produced by means of microwave-chemistry routes. Pure phases of SnS1-xSex (x = 0, 0.2, 1) have been synthesized in just 1 min by using microwave-hydrothermal synthesis. Moreover, Zn0.98M0.02O (M = Al, Ga) rods were formed by microwave-coprecipitation method in 5 min. Besides, 8 min of microwave-heating were enough for the combustion of Sr1-xLaxTiO3-δ (x = 0, 0.05, 0.1). In all cases, the utilization of microwave radiation produces high-quality phases. A comprehensive study of the structural, microstructural and thermoelectric properties of the microwave-synthesized materials is here performed by means of X-ray diffraction, SEM, HRTEM and temperature dependence measurements of Seebeck coefficient, electrical conductivity and thermal conductivity.Item SrMo0.9O3−δ Perovskite with Segregated Ru Nanoparticles Performing as Anode in Solid Oxide Fuel Cells(ACS Applied Materials and Interfaces, 2024) Cascos Jiménez, Vanessa Amelia; Chivite Lacaba, Mónica; Fernández-Díaz, María Teresa; Biskup Zaja, Nevenko; Alonso, José AntonioA new anode material, Ru-SrMo0.9O3−δ, with a perovskite structure and segregated metallic Ru, has been tested in an intermediate-temperature solid oxide fuel cell (IT-SOFC) in an electrolyte-supported configuration giving substantial power densities as high as 840 mW/cm2 at 850 °C using pure H2 as fuel. This material has been prepared by the citrate method and structurally and microstructurally characterized at room temperature by different techniques such as X-ray diffraction (XRD), neutron powder diffraction (NPD), scanning electron microscopy (SEM), and scanning transmission electron microscopy (STEM). NPD was very useful to determine oxygen positions and vacancies, unveiling a cubic and oxygen-deficient perovskite SrMo0.9O3−δ oxide with a Pm-3m space group and potential ionic mobility. On the other hand, SEM and STEM studies have allowed to identify metallic segregated Ru nanoparticles providing the material with an excellent catalytic activity. Other properties such as the thermal expansion coefficient (TEC) and chemical compatibility with other cell components or electrical conductivity have also been studied to understand the excellent performance of this material as anode in IT-SOFC and correlate it with the crystallographic structure.Item SrCo0.50Fe0.40Ir0.10O3−δ Decorated with Pd and La0.8Sr0.2Ga0.83Mg0.17O3−δ: A Cleaner Electrode for Intermediate-Temperature Solid Oxide Fuel Cells with Reduced Cobalt Content(ACS Applied Energy Materials, 2024) Chivite-Lacaba, Mónica; Prado Gonjal, Jesús De La Paz; Troncoso, Loreto; Alonso, José Antonio; Cascos Jiménez, Vanessa AmeliaRecent studies related to cathode materials for solid oxide fuel cells (SOFCs) have showcased the feasibility of stabilizing cubic or tetragonal perovskite phases in the SrCoO3−δ system at room temperature. This achievement has been facilitated by partially substituting Co atoms with small amounts of highly charged cations such as Ir4+ in SrCo0.90Ir0.10O3−δ. This specific material exhibits exceptional performance as a cathode for SOFCs operating at intermediate temperatures (800–850 °C). However, it contains a high amount of cobalt, which is both costly and toxic. In this study, our focus has been on further improving this material by reducing its cobalt content, resulting in a cleaner and more cost-effective cathode for SOFCs. The resulting SrCo0.50Fe0.40Ir0.10O3−δ perovskite, synthesized by the citrate method, introduces a 40% composition of Fe in the sites of Co and Ir, effectively decreasing the amount of Co in the material. The crystal structure of this perovskite oxide has been analyzed using X-ray diffraction (XRD) and neutron powder diffraction (NPD), allowing us to establish correlations with its mechanical and electrical properties. In the single-cell test, this material gave reasonable performances as a cathode at intermediate temperatures (800–850 °C), with La0.8Sr0.2Ga0.83Mg0.17O3−δ (LSGM) as the electrolyte. An analysis of the chemical compatibility between the cathode and the electrolyte, LSGM, demonstrated no interaction at elevated temperatures. Thermal expansion coefficient (TEC) measurements exhibited consistent linear expansion across the entire temperature range. Lastly, the perovskite displayed commendable electrical conductivity along with a promising power density measurement of 384 mW/cm2 at 850 °C. These findings collectively suggest the potential of this material as a viable cleaner cathode option for intermediate-temperature SOFCs. Moreover, the cathode was further optimized and the performance of the cell improved, by either infiltrating SrCo0.50Fe0.40Ir0.10O3−δ with a Pd(NO3)2 solution or mixing it with 30% of LSGM electrolyte, resulting in higher power densities (568 and 675 mW/cm2, respectively) in test cells fed with pure H2 as a fuel.- Project number: 121
Item Nuevos modelos cristalográficos y mineralógicos para impresoras 3D(2023) Pina Martínez, Carlos Manuel; López-Acevedo Cornejo, María Victoria; Ávila Brande, David; Prado Gonjal, Jesús De La Paz; Cascos Jiménez, Vanessa Amelia; Cabeza Llorca, Ana; Crespo López, Ángel; Fernández Sequeira, Fernando Vinicio; Otero Díaz, Luis Carlos - Project number: 24
Item Diseño de modelos cristalográficos y mineralógicos para impresoras 3D(2022) Pina Martínez, Carlos Manuel; Ávila Brande, David; Cabeza Llorca, Ana; Cascos Jiménez, Vanessa Amelia; Castillo Martínez, Elisabet; Crespo López, Ángel; López-Acevedo Cornejo, María Victoria; Otero Díaz, Luis Carlos; Pimentel Guerra, Carlos; Prado Gonjal, Jesús De La PazEl proyecto DISEÑO DE MODELOS CRISTALOGRÁFICOS Y MINERALÓGICOS PARA IMPRESORAS 3D es un proyecto de continuación de tres proyectos Innova-Docencia anteriores (nº 5, nº 98 y nº 24) y tenía como finalidad elaborar nuevos modelos cristalográficos y mineralógicos para su impresión mediante impresoras 3D. Item Al-Doped SrMoO3 Perovskites as Promising Anode Materials in Solid Oxide Fuel Cells(Materials, 2022) Cascos Jiménez, Vanessa Amelia; Fernández Díaz, María Teresa; Alonso, José AntonioTwo perovskite materials with SrMo1−xAlxO3−δ (x = 0.1, 0.2) compositions have been synthesized by reduction from the corresponding scheelite phases, with SrMo1−xAlxO4−δ stoichiometry; the pertinent characterization shows that the defective perovskites can be used as anode materials in solid oxide fuel cells, providing maximum output power densities of 633 mW/cm2 for x = 0.2. To correlate structure and properties, a neutron powder diffraction investigation was carried out for both perovskite and scheelite phases. Both perovskites are cubic, defined in the Pm-3m space group, displaying a random distribution of Mo and Al cations over the 1a sites of the structure. The introduction of Al at Mo positions produced conspicuous amounts of oxygen vacancies in the perovskite, detected by neutrons. This is essential to induce ionic diffusion, providing a mixed ionic and electronic conduction (MIEC), since in MIEC electrodes, charge carriers are combined in one single phase and the ionic conductivity can be one order of magnitude higher than in a conventional material. The thermal expansion coefficients of the reduced and oxidized samples demonstrated that these materials perfectly match with the La0.8Sr0.2Ga0.83Mg0.17O3−δ electrolyte, La0.4Ce0.6O2−δ buffer layer and other components of the cell. Scanning electron microscopy after the test in a real solid oxide fuel cell showed a very dense electrolyte and porous electrodes, essential requirements for this type of fuel. SrMo1−xAlxO3−δ perovskites are, thus, a good replacement of conventional biphasic cermet anodes in solid oxide fuel cells.