Direct conversion of CO₂ to ethylene by bifunctional ZnCr₂O₄-ZSM-22 catalyst

Although direct catalytic conversion of CO₂ to light olefins has attracted wide attention, oriented synthesis of single ethylene from CO₂ is still a challenge. In this work, an efficient bifunctional ZnCr₂O₄-ZSM-22 catalyst was developed for the direct conversion of CO₂ to ethylene. This catalyst exhibited 24.0% ethylene selectivity and 21.9% CO₂ conversion by one-pass. It is worth noting that the ratio of ethylene/light olefin (C-mol ratio) was more than 93%, higher than those of other zeolites. Moreover, the ZnCr₂O₄-ZSM-22 catalyst realized superior stability, where there was no significant deactivation during 60 h. In addition, the effects of various factors on the catalytic performances were also systematically investigated. This bifunctional ZnCr₂O₄-ZSM-22 catalyst opens a new avenue for direct conversion of CO₂ to ethylene.