Fabrication of a wide temperature Mn-Ce/TNU-9 catalyst with superior NH3-SCR activity and strong SO2 and H2O tolerance

A Mn-Ce co-doped TNU-9 (Mn-Ce/TNU-9) catalyst was synthesized via a simple ion exchange method and then its catalytic activity, water resistance and sulfur resistance were studied in the selective catalytic reduction of NOx with NH3 as the reducing agent (NH3-SCR). The results show that the NOx conversion of Mn-Ce/TNU-9 is higher than those of Mn/TNU-9 and Ce/TNU-9 at a wide temperature window (150-450 degrees C), corresponding to >94.0% conversion of NOx and >99% selectivity of N-2. The redox cycle of Mn4+ + Ce3+ <-> Mn3+ + Ce4+ improves the redox performance for the Mn-Ce/TNU-9 catalyst and facilitates electron transfer, which further accelerates the oxidation of NO to NO2 that could lead to the Fast SCR reaction, therefore increasing the SCR performance. Furthermore, the synergistic effect between TNU-9 and bimetals can also enhance the activity. In addition, the Mn-Ce/TNU-9 catalyst demonstrates excellent sulfur and water resistance due to the hydrophobicity of TNU-9 and the easy sulfation of Ce protected from the active site Mn. Moreover, Mn-Ce/TNU-9 has a very good catalytic stability. These results prove that the bimetallic catalyst prepared by TNU-9 as the carrier will have a broad application prospect in the field of environmental catalysis.

Automated summary

The Mn-Ce co-doped TNU-9 catalyst showed excellent catalytic performance in the NH3 selective catalytic reduction of NOx, with high NOx conversion rate and N-2 selectivity, as well as superior water and sulfur resistance. The use of TNU-9 as a carrier enhances the activity and stability of the bimetallic catalyst.