Enhancement of NO adsorption performance on zeolite via a facile modification strategy.

Adsorption is a promising technology for simultaneously capturing nitrogen oxides (NO) from flue gases and recycling NO as a profitable chemical, for which a robust and efficient adsorbent provides the key step for success in practical applications. This work reports the enhancement of NO adsorption performances with less cost of desorption energy on Cu-ZSM-5 zeolites prepared by a facile and rapid (690 s) modification method, the incipient-wetness impregnation coupled with microwave drying (IM). In comparisons to H-ZSM-5, Na-ZSM-5 and conventionally liquid-phase ion-exchanged counterparts under sub-1000 ppm NO feed concentrations and room temperature, the IM sample renders a record NO adsorption capacity (q) of 0.878 mmol/g from dry gas stream on zeolites, and an applicable q of 0.1 mmol/g from wet gas stream with a proper copper loading (2.1 wt%). The temperature programmed desorption of NO on the optimal IM sample saturated with NO from wet gas stream exhibit primary peak temperature lower than reported Cu-ZSM-5 and significant NO proportion (72.6 %) in desorbed NO. Deeper insights into advantageous NO oxidative adsorption over the properly-loaded Cu-ZSM-5 in terms of diverse adsorbate states and competitiveness towards HO were gained, showing IM method a promising sorbent improvement strategy for practical use.