Modélisation ab initio des matériaux : propriétés structurelles, optiques et catalytiques

Ab initio techniques allow exploring the structure-properties relationships without empiric parameters, and its combination with experimental characterization becomes a powerful tool in the design of materials with selected applications. I will present three examples of application:

• the spectroscopic properties of TiO₂: despite the wide use of titanium dioxide materials, some aspects of their optical properties are poorly known. I will present the research conducted in the group to elucidate structure-response relationships as regards photoactivity and unexpected behavior observed on titania-based materials.
• the study of materials at the nanoscale: the properties of nanosized materials, mainly the control of shape in metallic nanoparticles and the structural evolution cluster - nano - bulk in TiO₂ will be discussed. Insights obtained from the chemical bond analysis tools will be presented.
• the development of catalysts with enhanced redox properties: the purification of hydrogen for its use in fuel cells needs specific redox catalysts, among the most selective are the ceria-based materials. Doping ceria with gallium enhances considerably the reducibility of the material and the ability to split H₂, opening new perspectives for hydrogenation reaction over metal oxides in the absence of noble metals.