【Frontiers in HaiChuan Chemical Technology】New progress achieved by Lanzhou Institute of Chemical Physics in the hydrogenation of CO2 to produce high-carbon alcohols

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New progress achieved in the synthesis of high-carbon alcohols from CO2 via hydrogenation at Lanzhou Institute of Chemical Physics. Coupling the greenhouse gas CO2 with green hydrogen to produce high-value alcohols containing two or more carbon atoms (C2+OH) is an important approach for reducing CO2 emissions and meeting global energy and chemical demands. However, this process faces multiple challenges; the chemical inertness of CO2 and the complexity of the reaction network make precise control of C-C coupling a significant challenge. Although various systems such as precious metal catalysts and modified Fischer-Tropsch synthesis catalysts have been developed, the space-time yield of C2+OH using current catalytic systems still falls short of expectations; therefore, there is an urgent need to develop more efficient catalysts or design new reaction pathways. Building on previous studies on Ni-catalyzed hydrogenation of CO2 to produce C2+OH (Angew. Chem. Int. Ed., 2023, DOI: https://doi.org/10.1002/anie.202311335) and the catalytic hydroformylation of olefins to aldehydes using heterogeneous catalysts (J. Catal. 2025, DOI: 10.1016/j.jcat.2025.116095; J. Org. Chem, 2023, DOI: 10.1021/acs.joc.2c02105), the research group from the National Key Laboratory of Low-Carbon Catalysis and Carbon Dioxide Utilization at the Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, developed a Ni-K co-modified Fe-based catalyst (1Ni-4K/Fe). This catalyst enabled an space-time yield (STY) of 317.0 mg/g/h for the hydrogenation of CO2 to produce C2+OH, and it could operate stably for 300 hours ； On the other hand, by utilizing the concept of cascade catalysis, a three-in-series system of “CO2 hydrogenation – olefin hydroformylation – aldehyde hydrogenation” (1Ni-4K/Fe||Rh1/POPs||Cu@SiO2) was developed, which further converts the olefins in the products into alcohols. This approach achieved a space-time yield of C2+OH of 980.5 mg/g/h with a selectivity of 55.0%. Moreover, due to the carbon-enhancing effect of hydroformylation, the proportion of C3+OH among C2+OH reached 75.6%, thereby significantly improving the carbon utilization rate. Systematic studies have shown that in K-Ni co-modified Fe catalysts, the synergistic mechanism between K and Ni significantly enhances the space-time yield of C2+OH formation. The introduction of Ni promotes the formation of *CHx intermediates, while the presence of K inhibits the deep hydrogenation of *CHx; together, these effects enhance the coupling of *CO with *CHx. At the same time, the introduction of K and Ni can accelerate the formation of the active phase Fe5C2 and its in-situ recarburization; therefore, while exhibiting high activity, it also demonstrates good operational stability. To further improve the utilization rate of carbon atoms and the selectivity for C2+OH in the products, the researchers employed the concept of cascade catalysis to develop a tandem system consisting of two three-catalyst stages: \"CO2 hydrogenation – olefin hydroformylation – aldehyde hydrogenation\" (as shown in Figure 4), thereby converting all excess olefins in the products into corresponding aldehydes or alcohols. Compared to the single-stage 1Ni-4K/Fe catalyst, this tandem catalytic system achieves a C2+OH selectivity of 55.0%, with a space-time yield of 980.5 mg/g/h. Furthermore, thanks to the carbonation effect of the formylation reaction, the proportion of C3+OH in the total alcohols in this tandem system increased from 41.0% with a single catalyst to 75.6%.