Book Description
Climate change and global warming caused by the increasing emissions of greenhouse gases (such as CO2) recently attract attention of the scientific community. The combination of plasma and catalysis is of great interest for turning plasma chemistry in applications related to pollution and energy issues. In this chapter, our recent research efforts related to optimization of the conversion of CO2 and CO2/H2O mixtures in a pulsed surface-wave sustained microwave discharge are presented. The effects of different plasma operating conditions and catalyst preparation methods on the CO2 conversion and its energy efficiency are discussed. It is demonstrated that, compared to the plasma-only case, the CO2 conversion and energy efficiency can be enhanced by a factor of ∼2.1 by selecting the appropriate conditions. The catalyst characterization shows that Ar plasma treatment results in a higher density of oxygen vacancies and a comparatively uniform distribution of NiO on the TiO2 surface, which strongly influence CO2 conversion and energy efficiencies of this process. The dissociative electron attachment of CO2 at the catalyst surface enhanced by the oxygen vacancies and plasma electrons may explain the increase of conversion and energy efficiencies in this case. A mechanism of plasma-catalytic conversion of CO2 at the catalyst surface in CO2 and CO2/H2O mixtures is proposed.
