Modulating chemical compositions of nanostructured metal oxides for achieving high-performance catalysis

Abstract

Due to the global phenomenon of industrialization, there has been a rapid escalation in energy consumption, giving rise to pressing concerns related to environmental pollution and global warming. Addressing these issues and striving toward a clean future, extensive efforts are necessary. In order to achieve an eco-friendly and sustainable future, the development of various devices such as fuel cells, water electrolyzers, batteries, and sensors, as alternatives to existing conventional systems, becomes imperative. However, the commercialization of these technologies depends on high-performance catalysis, defined not only by enhanced activity but also by the incorporation of additional functionalities such as thermal/chemical stability, selectivity, reproducibility, and mass production capabilities. Metal oxides are fundamental materials applied to various devices that require high-performance catalysis based on their outstanding stability and electrical properties. In particular, the formation of heterostructures by integrating metal catalysts with metal oxides can profoundly enhance overall device performance through metal-support interactions (MSI). To maximize the performance driven by MSI, it is important to modulate the physicochemical properties of the constituent metal oxide. However, in typical heterostructures, it is challenging to manipulate specific factors independently due to structural complexity and randomly distributed interfaces. Moreover, the distinction of the intrinsic contribution of modulated properties toward improved catalysis is difficult because all other factors can affect overall performance simultaneously. Thus, here, in this dissertation, we report a novel strategy to precisely elucidate the role and influence of certain factors on high-performance catalysis. This is accomplished through the utilization of a well-defined platform, allowing for independent modulation of the chemical compositions of the metal oxide while fixing all other variables. Based on this, it was applied to real-life applications encompassing high-performance sensors, water electrolyzers, and energy conversion devices. The strategy demonstrated in this thesis can be expanded to various fields where the physicochemical properties of metal oxides play an important role, and are expected to effectively contribute to improving the overall performance with enhanced catalysis.