Surface chemistry studies of carbon dioxide with magnesium oxide and titanium dioxide

Abstract

There is significant interest in methods to aid in the removal of carbon dioxide from our environment. The methods range from sequestration to catalytic transformations. In sequestration, CO2 is collected from emission sources, and may be stored in a variety of materials including geological formations. Catalytic research often involves the transformation of CO2 to another compound such as methane. The majority of these latter studies focus on the use of photocatalysis for the conversion of CO2. An alternative method, discussed in this dissertation, is to examine the surface chemistry for the adsorption and thermal reduction of carbon dioxide with magnesium oxide and titanium oxide surfaces. We are also interested in gaining a better understanding of the refractory nature of CO2. The overall goal of these studies is to elucidate the surface reaction mechanism for the reaction of carbon dioxide on metal oxide surfaces with and without UV light. We combine the use of X-ray photoelectron and Auger electron spectroscopies to examine the surface chemistry of CO2. First, carbon dioxide is exposed to the heated metal oxide surface and the surface atomic concentrations are measured after reaction. The substrate temperature and CO2 exposure are varied in the experiment. Similar studies are also performed in the presence of UV light to gain a better understanding of photocatalysis. The results from these experiments will be discussed, as well as, the direction of future studies.