Directly Converting Syngas to Linear alpha-Olefins over Core-Shell Fe3O4@MnO2 Catalysts

摘要

Converting syngas to value-added chemicals via Fischer-Tropsch synthesis has attracted much attention, whereas the direct hydrogenation of CO to heavy olefins, especially linear alpha-olefins (LAOs), remains a challenge. In this study, we designed a core-shell Fe3O4@MnO2 catalyst to realize the direct conversion of syngas to LAOs with high efficiency. This catalyst exhibited a high selectivity of 79.60% for total alkenes and 64.95% for C-4(+) alkenes, 91% of which are LAOS, at a CO conversion of approximately 75%. Promotion of the electron transfer from MnO2 to Fe3O4 inside the core-shell Fe3O4@MnO2 catalyst facilitated the dissociative adsorption of CO molecules on Fe3O4 and the spillover of H atoms onto the MnO2, which enhanced C-C coupling, weakened the hydrogenation activity of the catalyst, and improved the production of LAOS. A superior stability over 100 h was observed, demonstrating the promising potential of this catalyst for industrial applications.