Chapter 16 - Noble Metal–Manganese Oxide Hybrid Nanocatalysts

Abstract

Manganese oxides have received a great deal of attention as a model compound due to their unique physical, chemical, structural, and thermodynamic properties. The catalytic activities of manganese oxides at the nanoscale dimension are dependent on their chemical compositions and crystallographic structures, as well as their morphologies and pore structures. Noble metal nanoparticles have, often, been doped or decorated into/on the manganese oxides, the resultant nanocomposites with enhanced thermal stability and sintering resistance exhibit two or more different functionalities that have garnered attention for their enhanced catalytic properties. The recent developments of structure-diversified manganese oxides and metal oxide nanohybrids have been reviewed to elucidate their representative catalytic applications, including catalytic conversion and sensing of CO, NOx, SOx, and other volatile organic compounds (VOCs), decomposition of ozone and hydrogen peroxide, organic reduction and oxidation, removal of bacterial pathogens, epoxidation of olefins, coupling reaction, photo-/electrochromics, and water splitting reaction. While the synergistic properties of the metal–manganese oxide conjugates have shown promising catalytic activity towards various chemical reactions, the mechanistic understanding has been obvious and far more sophisticated with our increased understanding and control of the atomic world. Emerging research directions and arenas are envisioned at the end to solicit greater exploitation of the versatile catalytic activities of manganese oxides and metal oxide hybrids for the sustainable development of the society.