Activity enhancement of acetate precursor prepared on MnOx-CeO2 catalyst for low-temperature NH3-SCR: Effect of gaseous acetone addition

Acetate (Ac) precursor enhances SCR performance of MnOx-CeO2 catalyst synthesized by hydrolysis driving redox method (3Mn1Ce-Ac). Gaseous acetone improves the NOx conversion and N2 selectivity over 3Mn1Ce-Ac catalyst above 150 °C. [Display omitted] MnOx-CeO2 catalysts are developed by hydrolysis driving redox method using acetate precursor (3Mn1Ce-Ac) and nitrate precursor (3Mn1Ce-N) for the selective catalytic reduction (SCR) of NOx by NH3. A counterpart sample (Cop-3Mn1Ce) was prepared by the NH3·H2O co-precipitation method for comparison purpose. Combining the results of physicochemical properties characterization and performance test, we find that the 3Mn1Ce-Ac catalyst with some nanorod structures is highly active for the deNOx process. The SCR activity of the 3Mn1Ce-Ac catalyst is more admirable than the 3Mn1Ce-N and the Cop-3Mn1Ce catalysts due to plentiful Lewis acid sites, excellent low-temperature reducibility, and superior surface area resulted from O2 generation during the preparation procedure. The 3Mn1Ce-Ac still exhibits the greatest performance for the deNOx process when gaseous acetone is in the SCR feed gas. The NOx conversion and N2 selectivity over the 3Mn1Ce-Ac are both improved by gaseous acetone above 150 °C due to the inhibition of SCR undesired side reactions (NSCR & C-O reactions) and “slow-SCR” process.