MnOx-TiO2 and Sn doped MnOx-TiO2 selective reduction catalysts prepared using MWCNTs as the pore template

The stability of MnO x based low temperature SCR catalysts remained to be a serious issue. This report explored use of multi-walled carbon nanotubes (MWCNTs) network with uniform structure as a “rigid” pore template for synthesis of mesoporous MnO x -TiO 2 SCR catalyst with high surface area and high stability. The results showed that MWCNT network imposed MnO x -TiO 2 catalyst a mesoporous porosity with a narrow pore size distribution centered on ∼13.2   nm and a surface area of 131.6   m 2   g −1 stabilized at 500   °C. The mesoporous structure was formed by interconnected nanoparticles, comprised of crystallized rutile TiO 2 core surrounded by amorphous MnOx , with an average diameter of ∼8   nm. The catalyst exhibited an excellent low temperature SCR activity and selectivity as well as high resistance to deactivation and poison by H 2 O and SO 2 . SnO 2 modification led to degradation of catalytic performance in low temperature (60–180   °C) side, but improvement at high temperature side (240–360   °C), especially at high gas velocity, which can be attributed to change in structure, reactivity of MnO x and surface acidity induced by SnO 2 addition.