Effect of surface hydroxyls on DME and methanol adsorption over γ-Al2O3 (hkl) surfaces and solvent effects: a density functional theory study

Methanol and dimethyl ether (DME) adsorption over clean and hydrated γ-Al₂O₃(100) and (110) surfaces was studied by using density functional theory (DFT) combined with conductor-like solvent model (COSMO) in gas phase and liquid paraffin. On clean γ-Al₂O₃ (100) and (110) surfaces, DME and methanol preferentially interact with Al3 and Al1 of the γ-Al₂O₃(110) and (100) surfaces, respectively. On hydrated γ-Al₂O₃(100) and (110) surfaces, the OH group can influence the adsorptive behavior of DME and methanol. The Al3 and Al1 active sites of the hydrated (110) and (100) surfaces are inactivated due to hydroxyl influence, respectively. Compared to the adsorption energies of DME and methanol adsorption over the clean and hydrated (110) and (100) surfaces in gas phase and liquid paraffin, it is found that the solvent effects can slightly reduce adsorptive ability.