Abstract:
As global climate change intensifies, increasing attention has been directed towards the research of CO
2 emission reduction strategies and technologies for its resource utilization. High-carbon olefins, serving as crucial raw materials in chemical production, are predominantly synthesized from non-renewable petroleum resources through processes such as catalytic cracking. However, the production of high-carbon olefins from fossil resources is characterized by high energy consumption and reliance on non-renewable feedstocks. A promising catalytic pathway lies in the hydrogenation of CO
2 to produce high-carbon olefins using renewable green hydrogen as a reductant. Nevertheless, due to the stability of the CO
2 molecule, the activation of the C-O bond during hydrogenation and the subsequent coupling of C-C bonds pose significant challenges. This tandem reaction process inevitably encounters issues such as low activity, high selectivity for byproducts, and poor catalyst stability. Iron-based catalysts exhibit favorable activity in both the reverse water-gas shift reaction (RWGS) and Fischer-Tropsch synthesis (FTS), combined with their low cost, ease of availability, and wide operating range, making them suitable for industrial applications. Modification of these catalysts can enhance their performance for specific reactions. Therefore, Fe-based or Fe-based composite catalysts can be utilized for the catalytic hydrogenation of CO
2 to high-value products, enabling the directed synthesis of high-carbon olefins from CO
2. This paper primarily focuses on the process route for producing high-carbon olefins via CO
2 hydrogenation, analyzing the research progress in Fe-based or composite catalysts from multiple perspectives, including element doping, support modulation, multi-active site construction, and process parameter optimization. It discusses the chain-growth mechanism of the catalysts and the primary factors influencing the selectivity of high-carbon olefins, providing insights for the development of efficient Fe-based catalysts. Additionally, the challenges and potential solutions facing the industrial application of CO
2 hydrogenation are prospected.