Development of nanostructured catalytic materials and their application to energy technology

Abstract

Nanostructured materials have received wide attention due to their unique and useful electronic, optical, and magnetic properties which can be applied to various fields. In particular, nanostructured catalytic materials with controlled size and shape exhibit outstanding physical and chemical properties that are fairly different from those of bulk counterparts. Therefore, controllable synthesis of nanostructured catalytic materials has attracted attention from researchers over the past two decades, because they usually show a combination of the properties associated with different metals. Interestingly, in many cases, there is a great enhancement in specific catalytic properties upon nanostructured materials due to synergistic effects. On the other hand, synthesis of high-qualified nanostructured materials with controllable size, morphology, composition, and structure has thus far not been well developed. Therefore, the main objective of this thesis focuses on the development of the high-qualified nanostructured catalytic materials via colloidal chemical synthetic method and their application to energy technology such as fuel cell and photocatalyst. Additionally, this thesis focuses on reducing the overall costs through the use of cheaper catalyst (noble metal-non noble metal) and improving the catalytic activity and stability at the same time. In chapter 2, highly monodisperse spherical 3 nm Pd-Cu alloy nanoparticles (NPs) were synthesized in high yield through the coreduction approach. The relative compositions of Pd and Cu could be tuned by control-ling the molar ratios between the metal precursors in the raw solutions. The carbon supported Pd-Cu NPs (Pd-Cu/C) were chemically dealloyed by acetic acid washing, which resulted in the formation of porous structures. The prepared Pd-Cu/C catalysts exhibited at least threefold enhancement of Pd mass activities compared with a commercial Pd/C catalyst toward formic acid oxidation in an acidic medium, and also show...