Ternary system with sandwich configuration facilitates aromatic production from CO₂ hydrogenation

Enhancing the selectivity of light olefin intermediates is crucial for efficiently synthesizing aromatic hydrocarbons from CO₂ hydrogenation. However, due to the limitations of Anderson-Schulz-Flory law, the oriented synthesis of light olefins over Fe-based catalysts is challenging. Herein, we creatively insert Y zeolite between the Fe-based catalyst and ZSM-5 zeolite to form a sandwich configuration. The excellent cracking function of sandwich Y zeolite enables the products before the aromatization to be concentrated in the light unsaturated hydrocarbons, leading to a high aromatic selectivity during the succedent aromatization processes. With the assistance of Y zeolite, the light olefin selectivity of the K-Fe catalyst increases from 30.8 % to 40.3 %. After combining with ZSM-5 zeolite, the aromatic selectivity of the ternary system is boosted from 27.6 % to 51.5 % compared to the bifunctional catalysts without Y zeolite. Our studies offer insightful guidance for the rational utilization of multifunctional zeolites to directly synthesize target products.