Ambient temperature oxidation of carbon monoxide is a vital reaction for life support in enclosed atmospheres such as submarines and spacecraft. This reaction is usually achieved through the use of two classes of catalyst. Firstly, mixed copper and manganese oxides designated ‘Hopcalite’ or CuMn2O4. Secondly, high surface area noble metal catalysts deposited on durable metal oxide supports. Both of these classes of catalyst are investigated in this thesis, with the aim of producing novel, reproducible, robust and active ambient temperature carbon monoxide oxidation catalysts. In this thesis, CuMn2O4 is sequentially doped and/or impregnated with low weightings (1-10%) of the transition metals V and Ce, noble metals Pd and Pt and metalloid Si in an attempt to improve activity and moisture resistance. It was observed that doped V, Ce, Pd and Si are catalytic poisons toward CuMn2O4. This is likely due to their interference in the Cu ↔ Mn redox mechanism. XRD investigations infer doped Pd is a structural promoter toward CuMn2O4, increasing surface area and decreasing catalyst crystalinity. Impregnation of noble metals Pt and Pd onto CuMn2O4 surface causes deactivation of the noble metals, most likely due to the oxidation of Pt and Pd by Mn. No novel catalyst tested in this thesis displayed increased resistance to moisture deactivation. Noble metals Pt and Pd were impregnated upon 3 mm diameter Al2O3 spheres and tested for ambient temperature CO oxidation activity. The positive synergy between the two metals is measured, and the most efficient Pt:Pd ratio is discovered to be ~ 1:4. A novel, atom efficient method, for synthesising Pt/Pd/SnO2/Al2O3 catalysts using tin oxalate was conceived of and investigated. Compared to existing reference catalysts, oxalate derived catalysts preformed favourably and can be described as equivalently active.