Nitrogen oxides (NOx) have been listed as one of the six common air pollutants by WHO, as they can cause a series of health and environmental problems. One primary source of NOx is from the exhaust of vehicles. Therefore, the abatement of nitrogen oxides (deNOx) has been a long-term goal for achieving better air quality worldwide. The most conventional approach to reducing NOx is using ammonia as the reductant with selective catalytic reduction (SCR) systems, where the NOx can be reduced to N₂ and H₂O. However, the current ammonia carriers often possess slow ammonia sorption kinetics and poor structural stability. In our previous work, we combined physi-sorbents (i.e., metal-organic frameworks (MOFs), zeolites) and chemi-sorbents (MgCl₂, CaCl₂, and SrCl₂) with various fabrication techniques, such as freeze casting and 3D printing. The obtained materials demonstrate improved kinetics and reliable structural stability.
 

ammonia,SCR,deNOx,MOF,graphene