Zr‐doped β‐MnO2 for Low‐temperature Selective Catalytic Reduction of NO by NH3: Preparation, Characterization and Performance

Nanowire‐MnO 2 and a series of Zr‐doped MnO 2 catalysts with different Zr/Mn molar ratios were successively prepared by hydrothermal and impregnation methods. The Zr‐doped MnO 2 catalyst with Zr/Mn molar ratio of 0.04 and calcination temperature of 400 °C, proved to be the optimal that possessed the highest low‐temperature denitration efficiency. It showed the NO conversion of ~92 % and N 2 selectivity of ~80 % at 150 °C. Characterization results demonstrated that the main active phase of the catalyst was β‐MnO 2 , Zr atoms interacted with Mn atoms, and Zr doping increased the structural defects, oxygen vacancies and weak acid sites, which effectively enhanced the low‐temperature denitration activity and N 2 selectivity of β‐MnO 2 , also improved the water and sulphur resistance to some extent.