Surface chemistry studies of the reaction of CO2 with MgO (100), TiO2(110), and TiO2(100)

摘要

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 presentation, 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 experiments is to elucidate the surface reaction mechanism for the reaction of carbon dioxide on metal oxide surfaces. We combine the use of X-ray photoelectron and Auger electron spectroscopies to examine the surface chemistry of CO2. 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. Electron microscopy is also used to characterize the form of carbon deposited. Both MgO (100) and TiO2 (100) and (110) single crystal substrates are used.