Selective Conversion of Syngas to Aromatics over Fe₃O₄@MnO₂ and Hollow HZSM-5 Bifunctional Catalysts

Abstract

Although considerable efforts have been made toward converting syngas to liquid fuels and value-added chemicals, selectively converting syngas to aromatics remains a big challenge because of severe deactivation and low selectivity. Here, we reported a bifunctional catalyst composed of Fe3O4@MnO2 and hollow HZSM-5, which could synthesize aromatics from syngas with a high selectivity of 57% at CO conversion >90%. The catalyst retained good stability for 180 h under industrially relevant conditions. The electron transfer from the Mn to Fe species in the core–shell Fe3O4@MnO2 catalyst promoted the formation of olefins intermediates, which were subsequently diffused onto the acid sites of HZSM-5, further converting to aromatics. Shortened channels and cavity structures of hollow HZSM-5 strengthened the diffusion of reactants and products, enhancing the catalyst stability via the suppression of carbon deposition. The present research provides insight into developing a potential bifunctional catalyst candidate for selectively converting syngas to aromatics.