【Frontiers of HaiChuan Technology】Dalian Institute of Chemical Physics achieves the hydrogenation of carbon dioxide at low temperatures to produce olefins

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According to news from the Dalian Institute of Chemical Physics, our institute has achieved the synthesis of olefins through the hydrogenation of carbon dioxide at low temperatures. Recently, the research team led by Researcher Sun Jian from the Group on Carbon Resource Small Molecules and Hydrogen Energy Utilization (DNL1905) made new progress in the study of hydrogenation of carbon dioxide to produce olefins. They designed and synthesized iron-based catalysts modified simultaneously with an electron donor, Na, and a structural modifier, Co. Their research showed that the synergistic effect of Na and Co promoted the in-situ carbonization of the iron catalyst under low-temperature reaction conditions (180 to 240°C), resulting in the formation of a trigonal NaCoFe alloy carbide, which significantly improved the catalytic efficiency for converting carbon dioxide into olefins. Against the backdrop of the \"dual carbon\" goals, achieving efficient activation and selective conversion of carbon dioxide is a highly challenging scientific issue. Olefins are important basic chemical raw materials, widely used in the production of plastics and synthetic rubbers as well as as intermediates for the manufacture of other chemicals. However, most of the current catalysts for the hydrogenation of carbon dioxide to produce olefins require high temperatures of 320 to 450°C, which results in high energy consumption during the process, easy aggregation of catalytic activity, and stability issues. Therefore, synthesizing olefins under low-temperature reaction conditions has significant practical value. In this work, the team adjusted the electronic and geometric structure of the Fe catalyst by using high levels of Na and low levels of Co, thereby promoting the formation of FexCoy alloy phases through iron species under low-temperature reaction conditions – this helps to stabilize more Fe active sites and facilitates carbonization during CO2 hydrogenation. Both experimental results and theoretical calculations demonstrate that the FexCoy alloy phase can be gradually carbonized in situ during the reaction to form new species with higher C-C coupling activity, namely the trigonal (FexCoy)5C2 alloy carbide. This catalyst can still stably catalyze the hydrogenation of CO2 to produce olefins even at reaction temperatures as low as 180°C; no significant deactivation was observed during 500 hours of stability testing, thereby significantly reducing the reaction temperature required for CO2 activation and C-C coupling to form olefins. Under preferential conditions, the space-time yield of olefins can reach up to 1829 mg/gcat/h. This work provides a new approach for the low-energy and high-efficiency conversion of CO2 into olefins. The relevant research results were published recently in Angewandte Chemie International Edition under the title “Low-temperature CO2 Hydrogenation to Olefins on Anorthic NaCoFe Alloy Carbides”, and were also selected as a Hot Paper. The first author of this article is Han Jianxiang, a doctoral student in Group DNL1905 at my institute. This work is supported by projects such as the **Key Research and Development Program**, the National Natural Science Foundation, and the Open Fund for the Joint Energy and Chemical Engineering Project of the Liaoning Binhai Laboratory. (Writing/Photos by Han Jianxiang)