SeO2 adsorption on CaO surface: DFT and experimental study on the adsorption of multiple SeO2 molecules

SeO 2 adsorption mechanisms on CaO surface were firstly investigated by both density functional theory (DFT) calculations and adsorption experiments. Adsorption of multiple SeO 2 on the CaO (001) surface was investigated using slab model. Based on the results of adsorption energy and surface property, a double-layer adsorption mechanisms were proposed. In experiments, the SeO 2 adsorption products were prepared in a U-shaped quartz reactor at 200   °C. The surface morphology was investigated by field emission scanning electron microscopy (FE-SEM). The superficial and total SeO 2 mass fractions were measured by X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES), respectively. The surface valence state and bulk structure are determined by XPS and X-Ray Diffraction (XRD). The experimental results are in good agreement with the DFT results. In conclusion, the fundamental SeO 2 chemisorption mechanisms on CaO surface were suggested.