Synthesis of liquid fuel via direct hydrogenation of CO2

Zhenhong He; Meng Cui; Qingli Qian; Jingjing Zhang; Huizhen Liu; Buxing Han

doi:10.1073/pnas.1821231116

Synthesis of liquid fuel via direct hydrogenation of CO₂

Proc Natl Acad Sci U S A. 2019 Jun 25;116(26):12654-12659. doi: 10.1073/pnas.1821231116. Epub 2019 Jun 10.

Authors

Zhenhong He^{1

2}, Meng Cui^{1

3}, Qingli Qian^{4

5}, Jingjing Zhang^{1

3}, Huizhen Liu^{1

3

5}, Buxing Han^{4

3

5}

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
² College of Chemistry and Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, Shaanxi, 710021, China.
³ School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; qianql@iccas.ac.cn hanbx@iccas.ac.cn.
⁵ Physical Science Laboratory, Huairou National Comprehensive Science Center, Beijing 101400, China.

Abstract

Synthesis of liquid fuels (C₅₊ hydrocarbons) via CO₂ hydrogenation is very promising. Hydrogenation of CO₂ to liquid hydrocarbons usually proceeds through tandem catalysis of reverse water gas shift (RWGS) reaction to produce CO, and subsequent CO hydrogenation to hydrocarbons via Fischer-Tropsch synthesis (FTS). CO₂ is a thermodynamically stable and chemically inert molecule, and RWGS reaction is endothermic and needs a higher temperature, whereas FTS reaction is exothermic and is thermodynamically favored at a lower temperature. Therefore, the reported technologies have some obvious drawbacks, such as high temperature, low selectivity, and use of complex catalysts. Herein we discovered that a simple Co₆/MnO_x nanocatalyst could efficiently catalyze CO₂ hydrogenation. The reaction proceeded at 200 °C, which is much lower than those reported so far. The selectivity of liquid hydrocarbon (C₅ to C₂₆, mostly n-paraffin) in total product could reach 53.2 C-mol%, which is among the highest reported to date. Interestingly, CO was hardly detectable during the reaction. The in situ Fourier transform infrared characterization and ¹³CO labeling test confirmed that the reaction was not via CO, accounting for the eminent catalytic results. This report represents significant progress in CO₂ chemistry and CO₂ transformation.

Keywords: CO2 hydrogenation; liquid fuel; lower temperature; paraffin; reaction pathway.

Publication types

Research Support, Non-U.S. Gov't