Multistage nanoreactor catalyst and preparation and application thereof

Abstract

The present disclosure discloses a multistage nanoreactor catalyst and preparation and application thereof, belonging to the technical field of synthesis gas conversion. The catalyst consists of a core of an iron-based Fischer-Tropsch catalyst, a transition layer of a porous oxide or porous carbon material, and a shell layer of a molecular sieve having an aromatization function. The molecular sieve of the shell layer can be further modified by a metal element or a non-metal element, and the outer surface of the molecular sieve is further modified by a silicon-oxygen compound to adjust the acidic site on the outer surface and the aperture of the molecular sieve, thereby inhibiting the formation of heavy aromatic hydrocarbons. According to the disclosure, the shell layer molecular sieve with a transition layer and a shell layer containing or not containing auxiliaries, and with or without surface modification can be prepared by the iron-based Fischer-Tropsch catalyst through multiple steps. The catalyst can be used for direct preparation of aromatic compounds, especially light aromatic compounds, from synthesis gas; the selectivity of light aromatic hydrocarbons in hydrocarbons can be 75% or above, and the content in the liquid phase product is not less than 95%; and the catalyst has good stability and good industrial application prospect.