Chain-like ZSM-5 zeolite coupled with Cu-Fe₃O₄ for CO₂ hydrogenation to light aromatics

The capture and utilization of carbon dioxide (CO₂) have attracted much attention in recent years; in particular, the direct hydrogenation of CO₂ to light aromatics has been considered as a potential route to produce high value-added chemicals. However, it is still a big challenge to adjust the aromatic distribution and achieve a high selectivity to the targeted products. In this work, a bifunctional catalyst that combines the Cu-modified Fe₃O₄ and the chain-like ZSM-5 zeolite is used for the hydrogenation of CO₂ to light aromatics. The catalyst components were characterized by XRD, SEM, TEM, ICP-AES, Py-IR and N₂ adsorption-desorption; the effect of acid density and length-to-diameter ratio (b-axis/ a-axis) of zeolite moiety on the selectivity and distribution of aromatic products was then investigated. The results indicate that the chain-like ZSM-5 zeolite moiety with high acid density and appropriate length-to-diameter ratio can promote the C–C coupling for CO₂ hydrogenation and inhibit the formation of CH₄, which can improve the selectivity to aromatics and the space time yield (STY) of toluene.