Achieving high conversion of syngas to aromatics

Realizing high CO conversion and high aromatics selectivity simultaneously in syngas-to-aromatics (STA) reaction is still challenging. Herein, we report a 57.5% CO conversion along with 74% aromatics selectivity over a composite catalyst consisting of Fe/ZnCr2O4 (Fe modified ZnCr2O4 spinel) oxide and H-ZSM-5 zeolite. Impregnation of only 3 wt% of Fe onto ZnCr2O4 can remarkably increase CO conversion without sacrificing the aromatics selectivity. Oxygen vacancy concentration is improved after impregnating Fe. The highly dispersed iron carbide species is formed during the reaction over Fe/ZnCr2O4 spinel oxide. The synergistic effect of oxygen vacancy and iron carbide results in a rapid formation of abundant oxygenated intermediate species, which can be continuously transformed to aromatics in H-ZSM-5. This study provides a new insight into the design of highly efficient catalyst for syngas conversion. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

By impregnating Fe onto ZnCr2O4, high CO conversion is achieved without sacrificing aromatics selectivity. The highly dispersed iron carbide species formed in synergy with oxygen vacancy accelerates the formation of oxygenated intermediate species, leading to high selectivity for aromatics production.