Indoor air quality has gained attention due to the dangerous effects on human health. This thesis targets the catalytic oxidation of carbon monoxide (CO) and volatile organic compounds (VOCs) over manganese-oxide catalysts engineered for high conversion at mild temperatures. Two polymorph supports, MnO₂ and Mn₂O₃, are prepared by Solution Combustion Synthesis (SCS) and Nanocasting (NC) and then modified with either Au or bimetallic Au–Cu nanoparticles to create metal–oxide interfaces that can enhance redox properties and activity. A comprehensive investigation links structure to performance: N₂ physisorption at −196 °C quantifies surface area and porosity, X-ray diffraction resolves phases and crystallite size, H₂-TPR probes reducibility, O₂-TPD assesses the lability and mobility of surface and bulk oxygen and EDX provides elemental mapping to verify Au dispersion across MnOₓ.