Bifunctional catalysts with versatile zeolites enable unprecedented para-xylene productivity for syngas conversion under mild conditions

The direct conversion of syngas to aromatics has received consider-able attention. The development of a highly active and stable catalyst with tunable selectivity for the synthesis of aromatics remains a great challenge, notwithstanding the understanding of the reaction mechanism. In this study, we fabricated a series of high-performance bifunctional catalysts comprising CoMnAl catalysts, which contain Co2C nanoprisms as the active phase, and versatile HZSM-5@silicalite-1 zeolites, with a hollow nanostructure and a scaly shell, for the transformation of syngas into aromatics. The catalysts achieve a CO conversion 70% under mild reaction conditions (280 degrees C, 2 MPa), with ultrahigh stability. The selectivity toward aro-matics is higher than 63% with <2.9% selectivity toward CH4, and the para-xylene (PX) fraction of the aromatics produced reaches 34.7%, leading to unprecedentedly high space-time yield of PX. Furthermore, the reaction pathway and the intermediates involved in the formation of the aromatic products are also determined.

Automated summary

We fabricated a high-performance bifunctional catalyst for the direct conversion of syngas to aromatics. The catalyst, comprising Co2C nanoprisms and HZSM-5@silicalite-1 zeolites, showed high activity and stability, achieving a high CO conversion and selectivity towards aromatics, leading to a high space-time yield of PX.