Answers are grounded in this paper and cite their sources.
The basicity of oxide surfaces is often associated with surface lattice oxygen anions. CO 2 is the standard probe molecule for investigating surface basicity, but limited information is available in the surface science literature concerning its interaction with well-defined (single crystal) oxide surfaces. On stoichiometric Cr 2 O 3 (101̄2), CO 2 interacts with cation/anion site pairs to form bidentate carbonates that are stable at room temperature. This site pair consists of five-coordinate Cr 3+ cations and three-coordinate O 2- anions on the clean, stoichiometric, nonpolar (101̄2) surface. Terminating the surface cations with chromyl oxygen (Cr O) via dissociative O 2 chemisorption breaks the interaction and gives rise to a weakly bound CO 2 moiety, tentatively identified as a “monodentate” CO 2 adsorbate bound to terminal chromyl oxygen sites. Differences in the coordination of these species make the heats of adsorption a poor measure of the basicity of surface oxide ions. Terminating the surface cations with chlorine adatoms blocks the interaction between CO 2 and the surface, and no uptake is observed.
No takes yet. Share an insight, caveat, or question.
Abee et al. (2001) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: