Designing silica-coated CoMn-based catalyst for Fischer-Tropsch synthesis to olefins with low CO2 emission
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作者
GAS-SHIFT REACTION; SELECTIVE CONVERSION; SUSTAINABLE PRODUCTION; SYNGAS; HYDROGENATION; PERFORMANCE; NANOPRISMS; MECHANISM; PROMOTER; SUPPORT
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刊物名称
Appl. Catal. B-Environ.
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年、卷、文献号
2021, 299, 120683
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关键词
GAS-SHIFT REACTION; SELECTIVE CONVERSION; SUSTAINABLE PRODUCTION; SYNGAS; HYDROGENATION; PERFORMANCE; NANOPRISMS; MECHANISM; PROMOTER; SUPPORT
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摘要
Co2C nanoprisms exhibit promising catalytic performance for Fischer-Tropsch synthesis to olefins (FTO) but with high CO2 selectivity (>40%). Herein, silica-coated CoMn-based catalyst was designed to limit CO2 production and remained Co2C nanoprisms as active sites unchanged. With a desired coating amount of silica, CO2 selectivity was significantly suppressed to 15.1 C% while enhancing olefins selectivity from 39.7 C% to 58.8 C%, which also shows at least 160 h of stability. It is suggested the silica-coating not only reduces the adsorption capacity of H2O, but also promotes the fast transfer of H2O away from active sites due to the higher adsorption energy of H2O on SiO2 surface, thus suppressing water-gas-shift-reaction (WGSR) activity. Moreover, the sodium promoter can counteract the H2-enrichment effect caused by SiO2-coating and largely restrain CH4 formation and olefins hydrogenation. This work provides an effective strategy to suppress CO2 formation and enhance the carbon efficiency of FTO process.
