New research progress on bifunctional catalysts for one-step direct production of low carbon olefins from syngas

The light olefins, mainly ethylene, propylene and butene, are basic building blocks in chemical industry. The direct conversion of syngas to lower olefins considered as a new significant and attractive process for producing lower olefins from non-petroleum resources, owing to its process simplicity and low energy consumption. The light olefins can be directly produced from syngas via two routes, namely, the Fischer-Tropsch to olefins (FTO) reaction and oxide-zeolite (OX-ZEO) bifunctional catalysis strategy (SDTO). This paper mainly reviews recent developments of SDTO, with emphasis on the effects of catalyst design, catalyst preparation and interphase renovation on reactivity. The targeting control of operating parameters such as H₂/CO ratio, temperature, pressure and contact for higher production of light olefins has also been clarified. Applications of new in situ, in real-time techniques to identify the structure-function relationship and the reaction mechanism are summarized. The recent progress including the applications of new in situ, real-time techniques to identify the structure-function relationship and the reaction mechanism are reviewed in detail. With this, the authors put forward insights into significant promising tendencies and confronting challenges in the strategy of OX-ZEO.