A research team led by Prof. PAN Xiulian and BAO Xinhe in Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences designed a new bifunctional catalyst, which could achieve the syngas conversion to ethylene with a high selectivity. Their findings were published in Angewandte Chemie-International Edition.

Accurately controlling the activation of CO as well as C-C coupling has always been the most challenging problem in syngas chemistry, which is also the key to efficiently utilize coal and natural gas.

Researchers focused on catalytic conversion of syngas to high valuable chemicals. To overcome the selectivity limit of syngas conversion based on traditional Fischer Tropsch process, recently they reported a novel catalyst concept of oxide-zeolite (OX-ZEO): by separating CO activation and C-C coupling onto oxide and zeolites respectively.

According to their previous work, this catalyst had enabled direct conversion of syngas to mixed light olefins (Science, ACS Catalysis) and to aromatics (Chemical Communication).

Syngas conversion can be effectively steered toward ethylene via ketene intermediates by the 8MR side pockets of MOR employing the ZnCrOx-MOR composite. (Image by JIAO Feng) 

In this work, researchers further modified the OX-ZEO catalyst with ZnCrOx-mordenite (MOR). And the syngas conversion can be effectively steered to ethylene with this catalyst.

The selectivity of ethylene alone among hydrocarbons reached as high as 73% at 26% CO conversion, which is higher than those reported in direct conversion and multi-step via Methanol To Olefins (MTO) processes.

This opens a new avenue for development of syngas-to-ethylene technology. Furthermore, it demonstrates that the versatility of the bifunctional OX-ZEO catalyst concept, which may be developed into a new technological platform for syngas chemistry.