DFT study of ethanol adsorption on CaO(0 0 1) surface

•The more favorable adsorption sites for are on one (or two) Ca cations.•C2H5OH-surface distance is in the range of 2.3–2.5 Å; with E ads is −1.12 (−1.14) eV.•The adsorbed OH group is 53% (51%) larger that its molecular distance.•Distances and BO are similar for CaOmolecule and CaOsurface.•Charge transfer occurs from O atom (2nd layer) to Ca ions (1st layer).