Removal of hydrogen sulfide (H2S) is a key step for biogas purification. Herein, the adsorption of H2S and methane (CH4) on anatase titanium dioxide (TiO2) has been studied by first principle calculations. It is found that TiO2 offers excellent capacity for the H2S/CH4 separation. Using force-field molecular dynamics, this high separation capacity has been examined at room temperature. (C) 2012 Elsevier B.V. All rights reserved.