Carbon dioxide adsorption on MgO(001)–CO2 kinetics and dynamics

Thermal desorption spectroscopy (TDS) and molecular beam scattering were used to characterize the adsorption kinetics and dynamics, respectively, of CO2 on MgO(001). X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy as well as low energy electron diffraction were used for sample characterization. TDS revealed two CO2 desorption peaks at 200 K and 260 K, consistent with carbonate decomposition. XPS of adsorbed CO2 did reveal one broad C1s structure at 289.4 eV which also indicates carbonate formation. Carbonates decompose into CO2, CO, and O2 as evident from multi-mass TDS. CO2 beam scattering indicates non-activated and precursor-mediated adsorption with a low impact energy adsorption probability of 0.74.