Effect of Metal Complexing on Mn-Fe/TS-1 Catalysts for Selective Catalytic Reduction of NO with NH₃

TS-1 zeolite with desirable pore structure, an abundance of acidic sites, and good thermal stability promising as a support for the selective catalytic reduction of NO with NH₃ (NH₃-SCR). Herein, a series of Mn-Fe/TS-1 catalysts have been synthesized, adopting tetraethylenepentamine (TEPA) as a metal complexing agent using the one-pot hydrothermal method. The introduced TEPA can not only increase the loading of active components but also prompts the formation of a hierarchical structure through decreasing the size of TS-1 nanocrystals to produce intercrystalline mesopores during the hydrothermal crystallization process. The optimized Mn-Fe/TS-1(R-2) catalyst shows remarkable NH₃-SCR performance. Moreover, it exhibits excellent resistance to H₂O and SO₂ at low temperatures. The characterization results indicate that Mn-Fe/TS-1(R-2) possesses abundant surface Mn⁴⁺ and Fe²⁺ and chemisorbed oxygen, strong reducibility, and a high Brønsted acid amount. For comparison, Mn-Fe/TiO₂ displays a narrower active temperature window due to its poor thermostability.