Highly efficient production of aromatics from C2H5Cl coupling with CO over H-zeolites

Value-added utilization of C2H6 as an important component of natural gas and petrochemical by-products has attracted much attention. Aromatic synthesis from C2H6 is a crucial direction but remains a significant challenge due to its high stability. Chloroethane (C2H5Cl) is an essential derivative of C2H6, which effectively solves the C-H bond activation of C2H6. Herein, we report a pathway for the synthesis of aromatics via the coupling of CO and C2H5Cl over H-ZSM-5. Up to 76% aromatics selectivity is achieved via the coupling strategy whereas it is only 40% with the traditional methods. The introduction of CO not only facilitates the conversion of C2H5Cl, but also enhances the selectivity to aromatics over H-ZSM-5. Cyclopentenone species are detected and proved to be the key intermediate leading to a markedly improved aromatics selectivity. The C-13 isotope tracing experiment reveals that CO participates in the formation of cyclopentenone species and aromatics. Furthermore, C2H4 formed from C2H5Cl has been observed to undergo carbonylation processes over H-ZSM-5. This work further expands the coupling reaction system between small molecule compounds and CO, providing an insight for natural gas conversion on H-zeolites.