DICP Scientists Realize One-Step and High-Yield Synthesis of Isoparaffins from Carbon Doxide Hydrogenation

It would be a sustainable way of replacing fossil fuels, reducing CO₂ emissions, and facilitating the storage of renewable energy, if H₂ used for converting CO₂ was supplied by water electrolysis with renewable electricity. To precisely control the activation of CO₂ as well as C-C coupling, has always been the most challenging problem in CO₂ hydrogenation, which is also the key to the high-efficient utilization of CO₂.

Recently, a research team led by Dr. SUN Jian and Prof. GE Qingjie at the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences realized a one-step high-yield synthesis of isoparaffins from CO₂ hydrogenation, catalyzed by a multifunctional Na–Fe₃O₄/HMCM-22 catalyst. Their findings were published in ACS Catalysis.

This team has focused on catalytic hydrogenation of CO₂ to high-value fuels and chemicals, and has achieved the direct hydrogenation of CO₂ to gasoline (Nature Communications), linear α-olefins (Communications Chemistry), and light olefins (Catalysis Science & Technology) by designing catalysts with multiple active sites.

Reaction scheme of isoparaffin synthesis and coke formation during CO2 hydrogenation. (Image by WEI Jian)

In this study, researchers enabled a well matching of three tandem reactions comprising reverse water-gas shift, C-C coupling and isomerization through designing a multifunctional Na–Fe₃O₄/HMCM-22 catalyst. They achieved a selectivity of 82% among hydrocarbons for C₄₊ hydrocarbons, of which isoparaffins could account for 74%, while CO selectivity was as low as 17% at a CO₂ conversion of 26%.

The unique pore structure and appropriate Brnsted acid properties of HMCM-22, which effectively suppressed aromatization whilst promoting isomerization, are responsible for their high yields to isoparaffins.

In addition, researchers explored the reaction scheme of isoparaffin synthesis and coke formation during CO₂ hydrogenation, and investigated the method for zeolite regeneration.

This study enriches the design of highly selective catalysts for CO₂ hydrogenation into high-value chemicals.

This work was supported by the National Natural Science Foundation of China, Strategic Priority Research Program of the Chinese Academy of Sciences, and the Youth Innovation Promotion Association of Chinese Academy of Sciences. (Text by WEI Jian)