Cu/Mn co-loaded hierarchically porous zeolite beta: A highly efficient synergetic catalyst for soot oxidation

A hierarchically porous zeolite beta has been designed via a facile combined surfactant-assisted hydrothermal treatment and subsequent alkali etching approach. High contents of the Cu and Mn species were then highly dispersed into the as-synthesized hierarchically porous zeolite beta. The prepared composite catalyst exhibits highly active, stable and recyclable catalytic performances for soot oxidation, and extraordinarily low T₅₀ (260 °C) and T₉₀ (300 °C) values can be achieved in the presence of NO. A synergetic catalytic effect between valence-varied active species Cuⁿ⁺ and Mnⁿ⁺ has been proposed, which features the promoted generations of highly active oxygen species O^-/O^2- and active intermediate NO₂. In addition, the obtained catalyst shows an excellent water resistance performance in soot oxidation due to the hydrophobic crystalline zeolite framework and the interaction between soot and water vapor.