Macroscopic assembly style of catalysts significantly determining their efficiency for converting CO2 to gasoline

Abstract

Although considerable efforts have been made in converting CO₂via hydrogenation to gasoline, the selectivity to high-quality gasoline with high C₅₊ isoalkane and low aromatics amounts remains a challenge. Here, the efficient conversion of CO₂ into gasoline is realized over a bifunctional Fe–Zn–Zr and HZSM-5 catalyst with a core–shell assembly style. The selectivity for gasoline (C₅₊ hydrocarbon) reaches 55.8% in total hydrocarbons, with 91.9% C₅₊ isoalkanes and only 5.2% aromatics in gasoline at 21.5% CO₂ conversion. It is demonstrated that the predominant performance of the bifunctional Fe–Zn–Zr@HZSM-5 catalyst depends strongly on the appropriate Brønsted acid sites and shell thickness of the zeolite as well as the core–shell structure. The good match of the acidity and shell thickness of the zeolite in the core–shell catalyst is vital for suppressing the undesired deep hydrogenation and aromatization reactions. Meanwhile, the core–shell structure not only favors the formation of gasoline and C₅₊ isoalkanes by controlling the consecutive secondary reactions, but also boosts the conversion of the oxygen compounds via the abundant interfaces of the two active components. Moreover, the Fe–Zn–Zr@HZSM-5 catalyst exhibits an extremely good stability for 100 h, providing a promising route for CO₂ utilization to obtain high-quality gasoline.