Eco-designed ZSM-5 zeolites: biomass-assisted modifications and catalytic evaluation through model reactions

This study evaluates the impact of biomass addition on the physicochemical properties of ZSM-5 zeolites. Three families of zeolites were synthesized hydrothermally: a reference zeolite without biomass, one with lignin, and another combining lignin and sugarcane bagasse. Biomass has been shown to modify the zeolite structure by reducing the crystal size, favouring aluminium incorporation within the framework and reducing the number of defects as internal silanols. These modifications are attributed to the chemical interactions between biomass and inorganic precursors present in solution. The catalytic performance of these zeolites was analysed in n-hexane cracking and in the methanol to olefin (MTO) reactions. Zeolites synthesized with biomass demonstrated improved catalytic stability and selectivity towards light olefins, thanks to an enhanced diffusion path. Lignin, in particular, helped minimize structural defects, thus improving the catalyst lifetime. The addition of biomass offers significant advantages for tailoring zeolite properties while using renewable and abundant resources. This innovative approach opens up interesting prospects for the sustainable design of catalytic materials. It also enables agricultural and industrial wastes to be recycled into high value-added applications, strengthening the links between green chemistry and industrial performance.