STUDY ON HC ADSORPTION AND DESORPTION PERFORMANCE OF Cu/β ZEOLITES

Abstract

Abstract: A series of Cu-modified β zeolites were prepared using the metal ion exchange method with β zeolite as the carrier. The effects of Cu loading on the hydrothermal structural stability, hydrocarbon (HC) adsorption performance, and oxidation performance of HC-trapping zeolites were investigated through characterization techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and N₂ adsorption-desorption isotherms, both before and after hydrothermal aging. The results indicate that an appropriate amount of Cu can be uniformly dispersed within the zeolite. The modified β zeolite exhibits significantly enhanced hydrothermal structural stability, increased C₃H₆ adsorption capacity and HC oxidation efficiency, while NH₂ adsorption capacity decreases. When the Cu mass fraction reaches 6.4%, the pore size of the β zeolite further decreases, leading to reduced C₇H₈adsorption capacity and HC oxidation efficiency. After 60 hours of hydrothermal aging at 800 ℃, the modified zeolite achieves NH₃，C₃H₆, and C₇H₈ adsorption capacities of 0.989, 0.337, and 8.99 mg/g, respectively, with an HC oxidation efficiency of 71%, all of which are significantly superior to those of the hydrothermally aged H-β zeolite.

Key words: cold-start, HC adsorption-desorption, β zeolite, copper-modification

References

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