Micro-structured Cu-ZSM-5 catalyst on aluminum microfibers for selective catalytic reduction of NO by ammonia

Selective catalytic reduction of NOx with NH3 (NH3-SCR) is one of the most efficient technologies to remove NOx emissions. The copper ion-exchanged zeolites with broad temperature windows and high N-2 selectivity are very promising for this process. In this work, we synthesized a series of microfibrous-structured Cu-ZSM-5/Al-fiber catalysts for SCR reaction by changing the Si/Al molar ratios. The in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) of NH3 adsorption results show that the Cu-ZSM-5/Al-fiber catalysts with higher Si/Al molar ratios have higher NH3 adsorption capacity. The subsequent NO adsorption results show that the amount of adsorbed bridged nitrates species is in accordance with the enhanced NOx degradation activity. At moderate temperature, Cu-ZSM-5/Al-fiber catalyst shows better NH3-SCR performance under higher gas hourly space velocity (GHSV), indicating microstructured Cu-ZSM-5 catalysts are more active at high-throughout conditions due to the enhanced mass transfer.