Hierarchical Cu-Mn/ZSM-5 with boosted activity and selectivity for n-butylamine destruction: Synergy of pore structure and surface acidity

Adjusting the catalytic degradation route of nitrogen-containing VOCs (NVOCs) is still a challenge as both the oxidation and reduction reactions are simultaneously involved. Herein, a series of hierarchical Cu-Mn/ZSM-5 materials with different pore structures and surface acidities were prepared via an impregnation method and adopted for catalytic n-butylamine destruction. Experimental results show that the CuMn/Z-2 sample has the highest activity and N2 selectivity, over which n-butylamine can be totally decomposed at 280 °C with N2 selectivity over 82%. The superior catalytic performance of CuMn/Z-2 is owing to its developed porosity (accelerating the oxidation process and inhibiting organic byproducts formation) and weak acidity (slight adsorption of NH3 and preventing the formation of N2O). In situ DRIFTS reveal that the catalytic destruction of n-butylamine over Cu-Mn/ZSM-5 obeys two parallel pathways of n-butylamine adsorbed on acidic sites with C-N cleavage and n-butylamine adsorbed on metal sites and oxidized to amide before alcohol.