Design and modular optimization of components in Molecular Solar Thermal (MOST) systems
- Autores: Alberto Giménez Gómez
- Directores de la Tesis: Diego Sampedro Ruiz (dir. tes.), Ignacio Funes Ardoiz (dir. tes.)
- Lectura: En la Universidad de La Rioja ( España ) en 2026
- Idioma: inglés
- Número de páginas: 185
- Títulos paralelos:
- Diseño y optimización modular de componentes en sistemas moleculares solares térmicos (MOST)
- Tribunal Calificador de la Tesis: Cristina García Iriepa (presid.), Raúl Losantos Cabello (secret.), Manuel Plaza Martínez (voc.)
- Programa de doctorado: Programa Oficial de Doctorado en Química
- Calificación: Sobresaliente Cum Laude
- Materias:
- Enlaces
- Tesis en acceso abierto en: Dialnet
- Tesis en acceso abierto en: investigacion.unirioja.es
- Resumen
- español
La presente tesis doctoral se centra en el avance de los sistemas de Almacenamiento Molecular de Energía Solar Térmica (MOST, por sus siglas en inglés), una tecnología basada en el uso de fotointerruptores moleculares capaces de capturar energía solar y almacenarla en forma de energía de tensión de enlaces químicos. El trabajo aborda de manera específica los desafíos asociados al par norbornadieno/cuadriciclano (NBD/QC), centrándose en la optimización de la reacción de retro-conversión mediante catálisis heterogénea y en la mejora de la sostenibilidad del sistema.
En la primera etapa de la investigación, se identificó la falta de métodos estandarizados para evaluar la eficiencia de los procesos de liberación de calor. Para ello, se desarrolló un protocolo basado en espectroscopía UV-Vis. Este método permitió realizar un cribado sistemático de una amplia biblioteca de catalizadores comerciales, evaluando parámetros críticos como la velocidad de reacción y la estabilidad del catalizador en disolución. Gracias a este protocolo, se determinó que los materiales basados en metales nobles, especialmente el platino sobre soportes de carbono, presentan una actividad superior en comparación con otros sistemas tradicionales.
Posteriormente, la tesis explora la ingeniería molecular de los fotointerruptores para superar la dependencia de disolventes orgánicos volátiles y de alta toxicidad, como el tolueno. Se diseñaron y sintetizaron nuevos derivados de norbornadieno funcionalizados con grupos amida simétricos. Estos compuestos demostraron no solo una excelente capacidad de almacenamiento energético y estabilidad térmica, sino también una solubilidad significativamente mejorada en disolventes polares como el etanol. Los estudios de irradiación y caracterización confirmaron que estos sistemas mantienen su funcionalidad en medios más sostenibles, acercando la tecnología MOST a condiciones de operación más seguras.
Finalmente, se profundizó en el diseño y caracterización de catalizadores heterogéneos de metales nobles (Pt, Pd, Rh, Au) soportados sobre carbono y alúmina. Mediante el uso de técnicas avanzadas como microscopía electrónica de transmisión (TEM), difracción de rayos X (XRD) y espectroscopía de fotoelectrones de rayos X (XPS), se correlacionó la estructura del catalizador con su actividad. Se concluyó que una baja carga metálica y el mantenimiento del estado de oxidación metálico (reducido) son fundamentales para maximizar la eficiencia de la reacción. Estos hallazgos establecen una base técnica para la implementación de dispositivos MOST que empleen catalizadores recuperables y disolventes de bajo impacto ambiental.
This doctoral thesis focuses on advancing Molecular Solar Thermal (MOST) energy storage systems, a technology based on molecular photoswitches capable of capturing solar energy and storing it as chemical bond strain energy. The work specifically addresses the challenges associated with the norbornadiene/quadricyclane (NBD/QC) couple, focusing on the optimization of the back-conversion reaction through heterogeneous catalysis and the improvement of the system's sustainability.
In the first stage of the research, a lack of standardized methods for evaluating the efficiency of heat release processes was identified. To address this, a protocol based on UV-Vis spectroscopy was developed. This method enabled a systematic screening of an extensive library of commercial catalysts, evaluating critical parameters such as reaction rate and catalyst stability in solution. Thanks to this protocol, it was determined that noble metal-based materials, particularly platinum on carbon supports, exhibit superior activity compared to other traditional systems.
Subsequently, the thesis explores the molecular engineering of photoswitches to overcome the dependence on volatile and highly toxic organic solvents, such as toluene. New norbornadiene derivatives functionalized with symmetric amide groups were designed and synthesized. These compounds demonstrated not only excellent energy storage capacity and thermal stability but also significantly improved solubility in polar solvents such as ethanol. Irradiation and characterization studies confirmed that these systems maintain their functionality in more sustainable media, bringing MOST technology closer to safer operating conditions.
Finally, the design and characterization of noble metal heterogeneous catalysts (Pt, Pd, Rh, Au) supported on carbon and alumina were investigated in depth. Using advanced techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), the catalyst structure was correlated with its activity. It was concluded that a low metal loading and the maintenance of the metallic (reduced) oxidation state are fundamental to maximizing reaction efficiency. These findings establish a technical foundation for the implementation of MOST devices using recoverable catalysts and low-environmental-impact solvents.
- English
This doctoral thesis focuses on advancing Molecular Solar Thermal (MOST) energy storage systems, a technology based on molecular photoswitches capable of capturing solar energy and storing it as chemical bond strain energy. The work specifically addresses the challenges associated with the norbornadiene/quadricyclane (NBD/QC) couple, focusing on the optimization of the back-conversion reaction through heterogeneous catalysis and the improvement of the system's sustainability.
In the first stage of the research, a lack of standardized methods for evaluating the efficiency of heat release processes was identified. To address this, a protocol based on UV-Vis spectroscopy was developed. This method enabled a systematic screening of an extensive library of commercial catalysts, evaluating critical parameters such as reaction rate and catalyst stability in solution. Thanks to this protocol, it was determined that noble metal-based materials, particularly platinum on carbon supports, exhibit superior activity compared to other traditional systems.
Subsequently, the thesis explores the molecular engineering of photoswitches to overcome the dependence on volatile and highly toxic organic solvents, such as toluene. New norbornadiene derivatives functionalized with symmetric amide groups were designed and synthesized. These compounds demonstrated not only excellent energy storage capacity and thermal stability but also significantly improved solubility in polar solvents such as ethanol. Irradiation and characterization studies confirmed that these systems maintain their functionality in more sustainable media, bringing MOST technology closer to safer operating conditions.
Finally, the design and characterization of noble metal heterogeneous catalysts (Pt, Pd, Rh, Au) supported on carbon and alumina were investigated in depth. Using advanced techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), the catalyst structure was correlated with its activity. It was concluded that a low metal loading and the maintenance of the metallic (reduced) oxidation state are fundamental to maximizing reaction efficiency. These findings establish a technical foundation for the implementation of MOST devices using recoverable catalysts and low-environmental-impact solvents.
- español
