Hydrophobic interfaces regulate iron carbide phases and catalytic performance of FeZnOx nanoparticles for Fischer-Tropsch to olefins
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作者
Liu, Xiaozhe; Lin, Tiejun; Liu, Peigong; Zhong, Liangshu
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刊物名称
APPLIED CATALYSIS B-ENVIRONMENT AND ENERGY
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年、卷、文献号
2023, 331, 1873-3883
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关键词
Liu, Xiaozhe; Lin, Tiejun; Liu, Peigong; Zhong, Liangshu
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摘要
Fischer-Tropsch to olefins (FTO) with controllable iron carbide phase and high carbon utilization efficiency for Fe-based nanocatalyst attracts great interest but remains challenge. Herein, we report that the metastable Fe7C3 phase can be effectively tailored by altering shell thickness of hydrophobic SiO2 over a core-shell nanostructured FeZn@SiO2-c nanocatalyst. X-Fe5C2 was the dominated iron carbide phase for FeZnO(x )and FeZn@SiO2 nano-catalysts, while numerous Fe7C3 phases existed for hydrophobic FeZn@SiO2-c nanospheres. Compared with FeZnOx, the CO2 selectivity of FeZn@ 4.1-SiO2-c decreased by > 70%, while 1.7-fold higher olefins selectivity was simultaneously obtained during syngas conversion process. The hydrophobic interface greatly suppressed the water-gas-shift reaction by promoting the quick diffusion of water, and the as-formed H-2-lean and CO-rich local chemical environment benefits the formation of Fe7C3 and olefins products. This work provides a promising strategy to design phase-stable Fe7C3 with improvement of carbon efficiency for Fe-based nanocatalysts.
