Co2C‐based catalysts with SiO2,γ‐Al2O3,and carbon nanotubes(CNTs)as support materials were prepared and evaluated for the Fischer‐Tropsch to olefin(FTO)reaction.The combination of catalytic performance and structu...Co2C‐based catalysts with SiO2,γ‐Al2O3,and carbon nanotubes(CNTs)as support materials were prepared and evaluated for the Fischer‐Tropsch to olefin(FTO)reaction.The combination of catalytic performance and structure characterization indicates that the cobalt‐support interaction has a great influence on the Co2C morphology and catalytic performance.The CNT support facilitates the formation of a CoMn composite oxide during calcination,and Co2C nanoprisms were observed in the spent catalysts,resulting in a product distribution that greatly deviates from the classical Anderson‐Schulz‐Flory(ASF)distribution,where only 2.4 C%methane was generated.The Co3O4 phase for SiO2‐andγ‐Al2O3‐supported catalysts was observed in the calcined sample.After reduction,CoO,MnO,and low‐valence CoMn composite oxide were generated in theγ‐Al2O3‐supported sample,and both Co2C nanospheres and nanoprisms were identified in the corresponding spent catalyst.However,only separated phases of CoO and MnO were found in the reduced sample supported by SiO2,and Co2C nanospheres were detected in the spent catalyst without the evidence of any Co2C nanoprisms.The Co2C nanospheres led to a relatively high methane selectivity of 5.8 C%and 12.0 C%of theγ‐Al2O3‐and SiO2‐supported catalysts,respectively.These results suggest that a relatively weak cobalt‐support interaction is necessary for the formation of the CoMn composite oxide during calcination,which benefits the formation of Co2C nanoprisms with promising catalytic performance for the sustainable production of olefins via syngas.展开更多
Syngas conversion to fuels and chemicals is one of the most challenging subjects in the field of C1 chemistry. It is considered as an attractive alternative non-petroleum-based production route. The direct synthesis o...Syngas conversion to fuels and chemicals is one of the most challenging subjects in the field of C1 chemistry. It is considered as an attractive alternative non-petroleum-based production route. The direct synthesis of olefins and alcohols as high value-added chemicals from syngas has drawn particular attention due to its process simplicity, low energy consumption and clean utilization of carbon resource, which conforms to the principles of green carbon science. This review describes the recent advances for the direct production of lower olefins and higher alcohols via syngas conversion. Recent progress in the development of new catalyst systems for enhanced catalytic performance is highlighted. We also give recommendations regarding major challenges for further research in syngas conversion to various chemicals.展开更多
A series of Co/SiO2 catalysts with different sodium （Na）loadings （0, 0.1, 0.2, 0.5 and I wt%） were prepared and evaluated for Fischer-Tropsch reaction to study the effect of Na on the catalyst structure and cataly...A series of Co/SiO2 catalysts with different sodium （Na）loadings （0, 0.1, 0.2, 0.5 and I wt%） were prepared and evaluated for Fischer-Tropsch reaction to study the effect of Na on the catalyst structure and catalytic performance. The addition of Na was found to decrease the catalytic activity and hydrocarbon selectivity, but increase CO2 selec- tivity due to the enhanced WGS activity. The addition of Na also resulted in higher selectivity to oxygenates （alco- hols and aldehydes） and O/P ratio as well as the shift of hydrocarbons to lower carbon numbers. Structure charac- terization revealed a decrease in the surface area and particles size for the calcined samples with the addition of Na. CozC was formed during the reaction process for the Na-promoted catalysts. As a result, a new Co/Co2C bifunc- tional active sites were generated for oxygenates formation leading to increasing oxygenates selectivity. In addition, the Co2C nanoparticles alone may also act as dual active sites for oxygenate formation at high reaction pressure over the promoted catalysts with high Na loading.展开更多
文摘Co2C‐based catalysts with SiO2,γ‐Al2O3,and carbon nanotubes(CNTs)as support materials were prepared and evaluated for the Fischer‐Tropsch to olefin(FTO)reaction.The combination of catalytic performance and structure characterization indicates that the cobalt‐support interaction has a great influence on the Co2C morphology and catalytic performance.The CNT support facilitates the formation of a CoMn composite oxide during calcination,and Co2C nanoprisms were observed in the spent catalysts,resulting in a product distribution that greatly deviates from the classical Anderson‐Schulz‐Flory(ASF)distribution,where only 2.4 C%methane was generated.The Co3O4 phase for SiO2‐andγ‐Al2O3‐supported catalysts was observed in the calcined sample.After reduction,CoO,MnO,and low‐valence CoMn composite oxide were generated in theγ‐Al2O3‐supported sample,and both Co2C nanospheres and nanoprisms were identified in the corresponding spent catalyst.However,only separated phases of CoO and MnO were found in the reduced sample supported by SiO2,and Co2C nanospheres were detected in the spent catalyst without the evidence of any Co2C nanoprisms.The Co2C nanospheres led to a relatively high methane selectivity of 5.8 C%and 12.0 C%of theγ‐Al2O3‐and SiO2‐supported catalysts,respectively.These results suggest that a relatively weak cobalt‐support interaction is necessary for the formation of the CoMn composite oxide during calcination,which benefits the formation of Co2C nanoprisms with promising catalytic performance for the sustainable production of olefins via syngas.
基金supported by the National Natural Science Foundation of China(91545112,21573271,21403278)Shanghai Municipal Science and Technology Commission,China(15DZ1170500)the Chinese Academy of Sciences(QYZDB-SSW-SLH035)
文摘Syngas conversion to fuels and chemicals is one of the most challenging subjects in the field of C1 chemistry. It is considered as an attractive alternative non-petroleum-based production route. The direct synthesis of olefins and alcohols as high value-added chemicals from syngas has drawn particular attention due to its process simplicity, low energy consumption and clean utilization of carbon resource, which conforms to the principles of green carbon science. This review describes the recent advances for the direct production of lower olefins and higher alcohols via syngas conversion. Recent progress in the development of new catalyst systems for enhanced catalytic performance is highlighted. We also give recommendations regarding major challenges for further research in syngas conversion to various chemicals.
基金This work has been supported by the National Natu- ral Science Foundation of China （Nos. 91545112, 21573271, 21403278）, Shanghai Municipal Science and Technology Commission, China （No. 15DZ1170500）and the Chinese Academy of Sciences （No. QYZDB- SSW-SLH035, Youth Innovation Promotion Association）.
文摘A series of Co/SiO2 catalysts with different sodium （Na）loadings （0, 0.1, 0.2, 0.5 and I wt%） were prepared and evaluated for Fischer-Tropsch reaction to study the effect of Na on the catalyst structure and catalytic performance. The addition of Na was found to decrease the catalytic activity and hydrocarbon selectivity, but increase CO2 selec- tivity due to the enhanced WGS activity. The addition of Na also resulted in higher selectivity to oxygenates （alco- hols and aldehydes） and O/P ratio as well as the shift of hydrocarbons to lower carbon numbers. Structure charac- terization revealed a decrease in the surface area and particles size for the calcined samples with the addition of Na. CozC was formed during the reaction process for the Na-promoted catalysts. As a result, a new Co/Co2C bifunc- tional active sites were generated for oxygenates formation leading to increasing oxygenates selectivity. In addition, the Co2C nanoparticles alone may also act as dual active sites for oxygenate formation at high reaction pressure over the promoted catalysts with high Na loading.
