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.

Automated summary

In this study, a series of Cu-ZSM-5/Al-fiber catalysts with different Si/Al molar ratios were synthesized and their performance in NH3-SCR reaction was studied. The higher Si/Al molar ratio catalysts showed superior NH3 adsorption capacity and enhanced NOx degradation activity. The microstructured Cu-ZSM-5 catalysts exhibited better NH3-SCR performance at moderate temperatures under higher gas hourly space velocity, indicating improved mass transfer properties.