Synthesis of Co doped MnO2 catalysts with the assist of PVP for low-temperature SCR
The MnO2-CoOx catalysts with different Mn/Co ratio were prepared using Polyvinyl Pyrrolidone (PVP) as an assistant to control the morphology of composite oxides and exposure crystal faces. The physic-chemical properties of catalysts were systematically characterized, and the catalytic activity of NH3-SCR and resistance of SO2/H2O were investigated. It was found that the rod-shaped catalysts are obtained at various Mn/Co radio and Mn-Co-0.2-PVP catalysts show the best low-temperature SCR catalytic activity, resulting from (110) exposed crystal surface, enhanced the number of surface Lewis acid sites, strong adsorption strength and quantity of NH3 and NO. Furthermore, Mn-Co-0.2-PVP showed good resistance to H2O and SO2 poison owing to having more low temperature (~200℃) NO desorption sites, which are beneficial to promote the de-NOx reaction and less affected by SO2.