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Title: Ambient temperature oxidation of carbon monoxide by copper-manganese oxide based catalysts
Author: Jones, Christopher D.
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2006
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The catalytic oxidation of carbon monoxide is an important reaction both commercially and scientifically. Copper-manganese oxides in the form of hopcalite have formed a cheap and accessible carbon monoxide abatement catalyst for the last 80 years. This thesis outlines the robust and reproducible preparation methods necessary for the formation of highly active species, with the heat treatment applied during the catalyst drying steps being identified as crucial for the formation of active species. The addition of metal cations (Co3+, Ni2+, Fe3+, Ag+) to the standard hopcalite formulation has given rise to many interesting properties including increased intrinsic activity, increased surface area and greater stability of catalytic activity with increased usage. The results of doping with a small quantity of cobalt produced materials that were amorphous to X-Ray Diffraction studies and with increased surface areas over the standard hopcalite. The dual positive effects of increased activity and prolonged catalyst stability were also brought about by the addition of cobalt (1-5% with respect to the quantity of copper present). The joint effect of precipitate ageing time and level of cobalt doping is also probed. The poisoning effect of water on the hopcalite and cobalt-doped hopcalite is reported, with the effect being identified as temporary and reversible in many cases. The mechanisms of oxidation and deactivation over hopcalite are probed using the Temporal Analysis of Products technique with the important relationship between lattice oxygen and catalytic activity being identified. The presence of cobalt is also shown to be important to the re-oxidation of a reduced hopcalite surface. Catalysts were produced that rivalled and often improved on the activity and stability of a presently available commercial catalyst.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available