This　research　aims　to　enhance　the　SO2　tolerance　of　manganese　oxide　(MnOx)　catalysts　for　low-temperature　selective　catalytic　reduction　(SCR)　de-NOx.　Based　on　the　deactivation　mechanism　of　MnOx,　we　target　at　the　promotion　of　the　byproduct　(NH4HSO4)　decomposition　and　the　inhibition　of　the　byproduct　(MnSO4)　formation.　To　achieve　this　target,　thermogravimetric　(TG)　and　temperature　programmed　desorption　of　SO2　(SO2-TPD)　are　performed　upon　as　many　as　21　kinds　of　single　metal　oxides　to　explore　the　potentially　effective　chemical　composition　as　the　additive　of　MnOx　catalysts.　The　TG　result　indicates　that　Al2O3　can　remarkably　decrease　the　thermal　stability　of　NH4HSO4.　In　addition,　the　SO2-TPD　analysis　reveals　that　the　formed　species　after　SO2　adsorption　are　weakly　adsorbed　on　Al2O3.　Thus,　Al2O3　is　selected　to　mix　with　MnOx　to　optimize　its　SO2　tolerance.　Further　experimental　results　demonstrate　that　the　proper　introduction　of　Al2O3　can　effectively　enhance　the　low-temperature　SCR　de-NOx　activity　and　the　SO2　tolerance　of　MnOx.　It　is　revealed　that　the　introduction　of　Al2O3　into　MnOx　can　not　only　facilitate　the　decomposition　of　NH4HSO4　but　also　lead　to　reduced　thermal　stability　of　the　adsorbed　SO2　species　to　some　extent.　As　compared　to　the　pristine　MnOx,　the　slight　introduction　of　Al2O3　as　the　additive　is　beneficial　to　the　low-temperature　SCR　de-NOx　activity　and　SO2　tolerance　of　MnOx.　©　2020　Elsevier　B.V.