Design, Synthesis, and Characterization of Transition Metal Oxide Based Functional Materials for Multi-Phase Catalytic Applications

In this thesis, the main focus lies on the nanotechnological synthetic approaches available to heterogeneous catalysis. The seven chapters provided discuss the usefulness of such approaches in multi-phase systems. We discuss several important topics, including the use of carbon nanotubes as support, ligand-free synthesis of metal nanoparticles, and surface chemistry in the production of active metal oxide nanoparticles with well-defined sizes and compositions as a way to control the surface hydrophobicity for use in moisture-saturated gas-phase CO oxidation. Additionally, we introduce the use of solid acids as catalysts for the production of biomass derived platform molecules. High conversion and selectivity can be achieved by controlling the surface area and Brønsted/Lewis acid sites of TiO2 nanoparticles. Next, we focus on the design and modification of manganese based nanomaterials for photo- and electrochemical water splitting reaction. We first demonstrate that using manganese oxide as support with gold nanoparticles can result in a strong enhancement of catalytic activity for the water oxidation reaction. The enhanced activity of manganese oxide strongly correlates with initial valence of Mn. In Chapter 5, we consider the production and modification of high surface area mesoporous materials and active phases. Reference is then made to the more complex active sites that can be created or carved on such supports by using organic structure-directing agents. Finally, we follow with discussing the ability to achieve multiple functionality in catalysis via the design of specific facet exposed manganese oxide nanoparticles. The active MnO facets with higher adsorption energy of oxygen species can largely promote electrocatalytic activity. We conclude with a personal and critical perspective on the importance of fully exploiting the synergies between nanotechnology and surface science to optimize the search for new catalysts and catalytic processes