Assisting effect of Al2O3 on MnOx for NO catalytic oxidation

Various Mn-based catalysts for NO oxidation were prepared using Mn Oas active compound,while Ti Oand AlOwere adopted as catalyst support.The performance of the catalysts was tested to study the effect of support on Mn-based catalyst activity.Performance of the catalysts followed as Mn/Al>Mn/Al>Mn/Ti>Mn/Ti>Mn O>AlOon the whole,indicating the synergism of Mn Oand AlOfor NO catalytic oxidation.Results were analyzed according to characterization data.Adsorbed oxygen on catalyst rather than lattice oxygen was detected as the active oxidizer for NO oxidation.As catalyst support,AlOprovided more sites to carry surface adsorbed oxygen than Ti O,resulting in the presence of more active oxygen on Mn O/AlOthan on Mn O/Ti O.Moreover,Mn O/AlOpossessed high surface area and pore volume,which greatly benefited the adsorption of NO on catalyst and further favored the oxidation of NO by active oxygen.All these advantages helped Mn/Al exhibited the best catalytic efficiency.