Investigation of SO2 and H2O poisoning over Cu-HPMo/TiO2 catalyst for Low temperature SCR: An experimental and DFT study

•A novel copper-doped phosphomolybdic acid catalyst (Cu-HPMo/TiO2) for low temperature selective catalytic reduction with NH3 was developed.•Cu(3)-HPMo/TiO2 with strong surface acidity could restrain the SO2 adsorption and improve its SO2 resistance.•Density functional method was used to study the adsorption state and competitive adsorption of SO2 and H2O molecules on the catalyst surface.•The Cu(3)-HPMo/TiO2 exhibits a typical core-shell structure which could improve its sulfur and water resistance.