Promoting effect of acid sites in hierarchical porous Pt/ZSM-5 catalysts for low-temperature removal of VOCs

A group of Pt/ZSM-5 catalysts with various SiO2/Al2O3 molar ratios was prepared and their catalytic activities for various VOCs catalytic oxidation were evaluated. It is found that for the deep catalytic oxidation of n-hexane and benzene, the Pt/ZSM-5(46) exhibits the highest activity by virtue of the balance between Pt0 content and Pt dispersion. The high Pt0 content and great dispersion of Pt in catalysts are beneficial for VOCs oxidation. However, as for deep catalytic oxidation of oxygen/nitrogen-containing VOCs, the strong and abundant acid sites benefits to their adsorption on the surface of catalysts, and Pt/ZSM-5(25) with the lowest SiO2/Al2O3 molar ratio exhibits the highest activity owing to the promoting effect of the acid sites. This comprehensive study exemplifies a promising strategy for the design and preparation of innovative catalysts applied to the low-temperature removal of VOCs.