Catalysis Today, Vol.148, No.3-4, 212-220, 2009
Surface science perspective of carbon dioxide chemistry-Adsorption kinetics and dynamics of CO2 on selected model surfaces
The adsorption or formation of CO2 on surfaces is important in a variety of industrial and environmental applications such as methanol synthesis, exhaust cleaning, CO2 capturing/sequestering, fuel cell poisoning, fuel synthesis, etc. For most of these processes, a deeper understanding of the kinetics and dynamics of CO2 adsorption on surfaces could help to optimize the performance of catalysts. Historically, most surface science studies have focused on CO rather than CO2 as the probe molecule, i.e., fundamental knowledge about CO2 adsorption is still needed. This paper will focus on summarizing a few fundamental properties of CO2 adsorption on a number of selected model systems recently studied in our group. In particular, metals (Cu, Cr) and metal oxide (ZnO, TiO2, CaO) single crystals as well as so-called model catalysts (Cu-on-ZnO, Zn-on-Cu) and nanocatalysts will be considered. The similarities and differences between metals and metal oxides will be highlighted as well as the effect of surface defects. An attempt to tie the different systems together by proposing structure-activity relationships rules will be made. Kinetics experiments and molecular beam scattering data are summarized, some of which have been modeled by Monte Carlo simulations and density function theory. (C) 2009 Elsevier B.V. All rights reserved.
Keywords:CO2 utilization;Surface science;Heterogeneous catalysis;Kinetics;Molecular beam scattering;Adsorption dynamics