CORE-SHELL IRON-BASED CATALYST USED FOR DIRECT PRODUCTION OF AROMATIC HYDROCARBONS FROM SYNGAS, AND PREPARATION METHOD AND APPLICATION THEREFOR

摘要

A core-shell iron-based catalyst used for the direct production of aromatic hydrocarbons from syngas, said catalyst using a nano-ZSM-5 molecular sieve having a silicon to aluminium ratio of 30-200 as the shell layer, and surface pre-modified nano-metal oxide particles as the core. The nano-metal oxide particles have a size of 1-3 nm and an even distribution, and the metal element content is 0.1-7 wt%. The aromatic hydrocarbons are C7-C11 aromatic hydrocarbons. The catalyst has a high CO conversion rate and high aromatic hydrocarbon selectivity, the CO conversion rate reaching 42.6%, and the aromatic hydrocarbon selectivity reaching 47.6% among total hydrocarbons and 78.1% in oil phases. In addition, the aromatic hydrocarbon product is concentrated, and the selectivity of the by-products CO₂ and CO₄ is low, the CO₂ selectivity being only around 18.9%, and the CO₄ selectivity being only around 14.0%. The present invention solves the problems in the prior art of low aromatic hydrocarbon selectivity and yield, high CO₂ and CO₄ by-product selectivity, and low CO utilization.