Design and Synthesis of Metallic and Metal Oxide Nanomaterials for Environmental Catalysis

Metallic and metal oxide nanomaterials are increasingly being used for air pollution control, remediation, and development of environmentally sustainable technologies. This research work focused on development of facile methods for synthesis of metallic and mixed-metal oxides for environmental catalysis. The dissertation consists of three sections. ^ The first part describes the preparation of bimetallic copper manganese oxides at ambient temperature using a novel redox method and their use for removal of carbon monoxide and volatile organic pollutants from dilute gas streams. The synthesized copper manganese oxides had high intrinsic catalytic activity attributed to a combination of factors including compositional homogeneity, poor crystallinity, and high surface area. Homogeneous incorporation of copper into the amorphous manganese oxide matrix enhanced the redox properties of the resultant bimetallic oxides. ^ The second part demonstrates bulk biosynthesis of colloidal iron and silver nanoparticles using a rapid, single step, and completely green biosynthetic method employing aqueous sorghum extracts as both the reducing and capping agent. The synthesized iron nanoparticles effectively degraded bromothymol blue, a model organic contaminant. The synthesized metallic silver nanoparticles were of high purity, highly crystalline, and are spherical with an average diameter of about 10 nm. The synthesized silver nanoparticles are therefore potentially useful for biological applications. ^ The third part describes the synthesis of sulfated metal and mixed metal oxides and their use for selective dehydration of various biomass resources to levuninate esters. These solid acid catalysts offer several advantages over mineral acids typically employed for biomass conversion including high selectivity, easy separation from products, and efficient recyclability.