On Feb. 5th, Science published online the latest findings by the team of Professor Ding Mingyue from WHU’s Institute of Technological Sciences on catalyzing and converting syngas. The research focused on the discovery of a new type of FeMn@Si catalyst, which could produce olefins with high selectivity and high yield from syngas by suppressing CO2 by-products.

An expert review entitled Designing the Right Protection was also published in Science. It held that the findings would bring high economic benefits and provide new solutions for reducing CO2 emissions and achieving carbon neutrality.

The article was entitled “A hydrophobic FeMn@Si catalyst increases olefins from syngas by suppressing C1 by-products”, with Xu Yanfei, a doctoral candidate from the School of Power and Mechanical Engineering as the first author, Professor Ding Mingyue as the corresponding author, and WHU as the single first author and corresponding institution.

Olefins are produced with high selectivity by syngas through hydrophobic FeMn@Si catalyst

Through Fischer-Tropsch synthesis (FTS), coal is converted into liquid fuels and high-carbon chemicals through syngas (CO and H2). This technology has dominated the coal chemical industry for nearly a century. However, water gas shift reaction usually occurs in this process, which will produce a large amount of CO2 and consume plenty of water, resulting in substantial energy consumption in the follow-up process. In addition, FTS is a strong exothermic reaction, which is prone to produce methane by-products and reduce the yield of high carbon products. About 50% of CO is converted into CO2（40%）and C1 by-products such as methane. The low utilization efficiency of carbon atoms seriously hinders energy efficiency and economic benefits. How to effectively reduce the generation of CO2 and C1 by-products such as CH4 and improve the selectivity of specific hydrocarbon products has always been a huge challenge in the international energy chemical industry.

The research team has created a new type of hydrophobic FeMn @ Si catalyst. Under the condition of industrial reaction (320 ° C and 2-3 MPa), olefins can be produced with high selectivity directly from syngas. The carbon dioxide and C1 by-products such as methane were significantly reduced to below 22.5%. The selectivity of olefin could reach 65% (the selectivity of high added value α-olefin could peak above 81%), and the yields of olefin could reach above 36%.

It was found that the SiO2 hydrophobic layer on the surface of the FeMn@Si catalyst could protect the active phase from water oxidation and maintain its stable activity. At the same time, the hydrophobic layer on the catalyst surface prevented the water from entering the nuclear layer reaction region, thus inhibiting the water-gas shifting reaction (CO + H2OCO2+ H2) and significantly reducing the generation of carbon dioxide by-products.

In addition, the electron transfer of manganese metal additives to the surface of the Fe active phase in the nuclear layer significantly improved the selectivity of olefin products and inhibited the generation of methane by-products. The highly efficient coordination between the active phase of iron carbide in the nuclear layer and the hydrophobic shell would contribute to a series of new-type composite catalysts. By inhibiting the production of water-gas shifting reaction, the carbon dioxide emissions would be reduced, and the utilization efficiency of carbon atoms would be improved. Thus, syngas is expected to produce high value-added products such as olefins, aromatics, gasoline, jet fuel and so on in an efficient and economical manner.

The co-authors included Li Yongwang, Yang Yong, Wen Xiaodong and others from the Institute of Coal Chemistry in the Chinese Academy of Sciences in Shanxi, and Synfuels China Technology Co., Ltd. The research was funded by the National Natural Science Fund, the National Key R&D Program of China, the Science and Technology Program of Guangdong Province, and the Basic Science and Technology Program of Shenzhen City.

Professor Ding Mingyue’s team

Rewritten by: Cao Mi

Edited by: Qin Shihan

Link to the paper: https://science.sciencemag.org/content/371/6529/610

Link to the review: https://science.sciencemag.org/content/371/6529/577