Synthesis of aromatics from syngas over FeMnK/SiO 2 and HZSM-5 tandem catalysts

Abstract Direct synthesis of aromatics from syngas was studied by a tandem catalyst of FeMnK/SiO 2 with HZSM-5. A decrease in SiO 2 /Al 2 O 3 ratio of HZSM-5 decreased the crystal sizes of the tandem catalyst, restraining the reduction of iron oxides. Especially, The HZSM-5 with lower SiO 2 /Al 2 O 3 ratio promoted the formation of strong Bronsted acid sites (BAS). There existed a linear relationship between the BAS amount and aromatics selectivity. Increasing reaction temperature facilitated the formation of aromatics while the increase in both gas space velocity (GHSV) and pressure restrained the selectivity of aromatics. The tandem catalyst of FeMnK/SiO 2 with HZSM-5 presented excellent STA performances of 83.80% CO conversion and 57.17% aromatics selectivity under optimizing reaction conditions of 320 °C, 2.0 MPa and 4000 h −1 . This work indicated that a combination of Fe-Mn based catalyst with HZSM-5 could promote the direct conversion of syngas to aromatic hydrocarbons.