Yongzhi Zhao, Yihan Ye, Jingyao Feng, Yilun Ding, Xianquan Li, Daoning Wu, Tao Peng, Jiaqi Qu, Xin Huang, Zhaochi Feng, Guangjin Hou, Dengyun Miao, Xiulian Pan
The bottom-up strategy shows great potential to build up environmentally benign gasoline-range isoparaffins directly from syngas. Herein, we report that Fe-substituted MFI zeolite could significantly enhance the selective formation of gasoline in comparison to the conventional MFI and extra-framework Fe-modified MFI. CO conversion reaches 42.5% and C5-C11 selectivity 77.0%, corresponding to a space-time-yield (STY) 10.8 mmolC/(gcat·h) with CH4 selectivity only 1.1% at a space velocity of 3000 mL/(g·h). Characterizations with UV-vis spectroscopy (UV-vis), UV-Raman spectroscopy, x-ray absorption spectroscopy (XAS), magic-angle-spinning (MAS) nuclear magnetic resonance (NMR), H2 temperature-programmed reduction (H2-TPR), and Fourier-transform infrared spectroscopy (FTIR) demonstrate that ferric species are atomically dispersed within the MFI framework, generating Si─OH─Fe Brønsted acid sites. Butene model reactions and theoretical calculations reveal that the enhanced activity could be attributed to the facilitated methylation of olefins with ketene. This study provides fundamental understanding of the chain growth process in OXZEO catalysis and offers guidance for the rational design of catalysts for the production of high-quality gasoline from syngas.