Direct conversion of syngas into light aromatics over Cu-promoted ZSM-5 with ceria–zirconia solid solution

Abstract

In this study, ZSM-5 zeolite modified with copper and silica combined with ceria–zirconia solid solution (CZS) was used as a bifunctional catalyst for syngas conversion into light aromatics. The copper had enhanced dispersion on ZSM-5 with decreasing the loading to 0.5%, and Lewis acidity on the ZSM-5 surface could be generated by the introduced Cu⁺ and Cu²⁺ species at the exchange sites, over which the aromatization could be enhanced. A high selectivity to aromatics of 72.1% with a CO conversion of 40.8% at 450 °C and 3.6 MPa was achieved. Coke formation in the CZS/Cu-ZSM-5 catalyst was inhibited due to the decreased strong acid density as well as the promoted conversion of the intermediates after introducing copper to the ZSM-5 surface, leading to an enhanced stability and regenerability of this catalyst.