Nickel and potassium co-modified β-Mo2C catalysts were prepared and used for CO hydrogenation reaction. The major products over β-Mo2C were C1-C4 hydrocarbons, only few alcohols were obtained. Addition of potassium ...Nickel and potassium co-modified β-Mo2C catalysts were prepared and used for CO hydrogenation reaction. The major products over β-Mo2C were C1-C4 hydrocarbons, only few alcohols were obtained. Addition of potassium resulted in remarkable selectivity shift from hydrocarbons to alcohols at the expense of CO conversion over β-Mo2C. Moreover, it was found that potassium enhanced the ability of chain propagation with a higher C2＋OH production. Modified by nickel,β-Mo2C showed a relatively high CO conversion, however, the products were similar to those of pure β-Mo2C. When co-modified by nickel and potassium,β-Mo2C exhibited high activity and selectivity towards mixed alcohols synthesis, and also the whole chain propagation to produce alcohols especially for the stage of C1 OH to C2OH was remarkably enhanced. It was concluded that the Ni and K had, to some extent, synergistic effect on CO conversion.展开更多
The advancement of cost-effective and selective electrocatalyst towards CO_(2) to CO conversion is crucial for renewable energy conversion and storage,thus to achieve carbon-neutral cycle in a sustainable manner.In th...The advancement of cost-effective and selective electrocatalyst towards CO_(2) to CO conversion is crucial for renewable energy conversion and storage,thus to achieve carbon-neutral cycle in a sustainable manner.In this communication,we report that CujSb decorated Cu nanowire arrays on Cu foil act as a highly active and selective electrocatalyst for CO_(2) to CO conversion.In CO_(2)-saturated 0.1 M KHCO_(3),it achieves a high Faraday efficiency(FE)of 86.5%for CO,at-0.90 V vs.reversible hydrogen electrode(RHE).The H_(2)/CO ratio is tunable from 0.08:1 to 5.9:1 by adjusting the potential.It is worth noting that HCOO-product was totally suppressed on such catalyst,compared with Sb counterpart.The improving selectivity for CO could be attributed to the bimetallic effect and nanowire arrays structure.展开更多
Human activities and industrial emissions have markedly intensified the concentration of CO_(2)in the atmosphere,projected to reach 500 parts per million by 2045,thereby worsening global issues such as climate change ...Human activities and industrial emissions have markedly intensified the concentration of CO_(2)in the atmosphere,projected to reach 500 parts per million by 2045,thereby worsening global issues such as climate change and extreme weather events.To tackle these challenges,substantial efforts have been dedicated to developing efficient methods for converting the abundant and frequently underutilized one-carbon resource,such as CO_(2),to complex compounds.Currently,two main approaches exist to achieve this goal:chemical and biological methods.展开更多
This research investigates the use of biochar derived from agricultural waste as a support material for Fe-based(Fe-Co-K)catalysts,with and without Zn,in CO and CO_(2)hydrogenation,benchmarking its performance against...This research investigates the use of biochar derived from agricultural waste as a support material for Fe-based(Fe-Co-K)catalysts,with and without Zn,in CO and CO_(2)hydrogenation,benchmarking its performance against commercial activated carbon.Under semi-industrial Fischer-Tropsch conditions,biochar-supported catalysts,particularly the Zn-enhanced variant(ZFCK@C),delivered superior catalytic outcomes.The catalysts were prepared using ultrasound-assisted dissolution and incipient wetness methods and characterized using FTIR,XRD,BET,H_(2)-TPR,CO_(2)-TPD,XPS,and TEM.In CO hydrogenation at 340◦C and 20 bar,ZFCK@C achieved a remarkable 97%conversion,with 32%longer hydrocarbons selectivity(C_(5+)),39.6%olefins distribution(C_(5+)),an O/P ratio of 4.0,and 45.3%gasoline-range(C_(5)-C_(12))hydrocarbons distribution.For CO_(2)hydrogenation at 340◦C and 30 bar,the catalyst showed 40%conversion,low CH_(4)selectivity(6.1%),high C_(5+)selectivity(45%),38.7%olefins distribution(C_(5+)),an O/P ratio of 3.2,and 45.3%kerosene-range(C6-C16)hydrocarbons dis-tribution.Stability testing over 100 h demonstrated excellent durability with no significant deactivation or sintering,making the catalyst viable for extended industrial use.展开更多
In this study, different methods were used to prepare MoO3/ZrO2 catalysts for sulfur resistant methanation reaction. It was found that MoO3/ZrO2 catalyst prepared by one-step co-precipitation method achieved high meth...In this study, different methods were used to prepare MoO3/ZrO2 catalysts for sulfur resistant methanation reaction. It was found that MoO3/ZrO2 catalyst prepared by one-step co-precipitation method achieved high methanation performance. CO conversion could reach up to 90% on 25 wt% MoO3/ZrO2 catalyst, much higher than that on the conventional 25 wt% MoO3/Al2O3 catalyst. The Mo-based catalysts were characterized by XRF, XRD, Raman, BET, TEM and H2-TPR etc. It was found that MoO3 particles were highly dispersed on ZrO2 support for 25 wt% MoO3/ZrO2 catalyst prepared at 65-85℃ because of its relatively larger pore size, which contributed to a high CO conversion. Meanwhile, when MoO3 loading exceeded the monolayer coverage, the formed crystalline MoO3 and ZrM020g might block the micropores of the catalyst and make the methanation activity declined. These results are useful for preparing highly efficient catalyst for CO methanation process.展开更多
Metal-organic frameworks(MOFs) as a type of crystalline heterogeneous catalysts have shown potential application in photocatalytic CO_(2)reduction.However,MOF catalysts with high efficiency and selectivity are still i...Metal-organic frameworks(MOFs) as a type of crystalline heterogeneous catalysts have shown potential application in photocatalytic CO_(2)reduction.However,MOF catalysts with high efficiency and selectivity are still in pursuit.Herein,by a bimetallic strategy,the catalytic performance of a Co-MOF for photocatalytic CO_(2)reduction was enhanced.Specifically,the Co-MOF based on 4,5-dicarboxylic acid(H;IDC) and4,4’-bipydine(4,4’-bpy) can catalyze CO;reduction to CO,with high efficiency but relatively low selectivity.After replacement of 2/3 Co(Ⅱ) with Ni(Ⅱ) within Co-MOF,the resulted isostructural Co_(1)Ni_(2)-MOF not only retains high efficiency for photocatalytic CO_(2)reduction,but also shows enhanced CO selectivity.The CO evolution rate reaches 1160 μmol g^(-1)h^(-1)and the CO selectivity reaches as high as 94.6%.The enhanced photocatalytic CO_(2)reduction performance is supported by theoretical calculation results.This case demonstrates that bimetallic strategy is an effective mean to optimize the catalytic performance of MOF catalysts for photochemical CO_(2)reduction.展开更多
16.6%Co/γ-Al2O3 catalysts prepared by incipient wetness impregnation method were used for Fischer-Tropsch synthesis. The support was pre-treated with different concentration of NH4NO3 aqueous solution. The effect of ...16.6%Co/γ-Al2O3 catalysts prepared by incipient wetness impregnation method were used for Fischer-Tropsch synthesis. The support was pre-treated with different concentration of NH4NO3 aqueous solution. The effect of support pre-treatment on the properties of support and performance of supportedcobalt-based catalysts was investigated. To treat the support with NH4NO3 aqueous solution enlarged the pore of γ-Al2O3, decreased the impurity Na2O content, and weakened the surface acidity of γ-Al2O3. The change in the properties of the support decreased the interaction between cobalt species and support, enhanced the CO hydrogenation rate and the C5＋ selectivity. For all catalysts, increasing the reaction temperature increased the CO hydrogenation rate or the CO conversion, slightly decreased the total hydrocarbon selectivity, and favored the formation of methane and light hydrocarbons, while the chain growth probability decreased. For 16.6%Co/γ-Al2O3 catalysts, prepared with the support treated with 100 g/L NH4NO3 aqueous solution, the CO conversion, the CH4 selectivity, and the C5＋ selectivity were 83.13%, 6.86% and 82.75% respectively, and the chain growth probability was 0.83 under the condition of 493 K, 1.5 MPa, 500 h-1 and the molar ratio of H2 to CO being 2.0 in feed.展开更多
Structural and compositional design of core-shell structure is an effective strategy towards enhanced catalysis.Herein,amorphous MnO2 nanosheets and K+-intercalated layered MnO2 nanosheets are controllably assembled o...Structural and compositional design of core-shell structure is an effective strategy towards enhanced catalysis.Herein,amorphous MnO2 nanosheets and K+-intercalated layered MnO2 nanosheets are controllably assembled over Fe2O3 spindles,in which the MnO2 nanosheets are perpendicularly anchored to the surface of Fe2O3.Such a core shell structure contributes to a high specific surface area and abundant pore channels on the surface of catalysts.In addition,the existence of K+provides large numbers of basic sites and restrains the formation of unpleasant(Fe1-xMnx)3O4.Benefiting from the merits in structure and composition,CO adsorption is enhanced and remaining time of intermediates is prolonged on the surfaces of catalysts during the Fischer–Tropsch synthesis(FTS),facilitating to the formation of active iron carbides and C–C coupling reactions.Resultantly,the Fe2O3@K+-Mn O2 shows both a high CO conversion of 82.3%and a high C5+ selectivity of 73.1%.The present study provides structural and compositional rationales on design high-performance catalysts towards FTS.展开更多
Two K/Mn-MgO supported catalysts were prepared by Fe（CO）5 and Fe（NO3）3 as precursor respectively. The obtained Fe-K/Mn-MgO catalysts were tested for CO hydrogenation to light alkenes and characterized by X-ray pow...Two K/Mn-MgO supported catalysts were prepared by Fe（CO）5 and Fe（NO3）3 as precursor respectively. The obtained Fe-K/Mn-MgO catalysts were tested for CO hydrogenation to light alkenes and characterized by X-ray powder diffraction （XRD）, X-ray photoelectron spectra （XPS）, H2 temperature-programmed reduction （H2-TPR）, H2 CO and CO2 temperature-programmed desorption （H2, CO/CO2-TPD） and transmission electron microscope （TEM） The results indicated that the catalyst with 10 wt% Fe loading prepared by Fe（CO）5 as precursor showed better performance in syngas to light alkenes than ones obtained from Fe（NO3）3 as precursor, where the CO conversion was 62.50% and the selectivity was 55.95% at 350 ℃, 1.5 MPa and 1000 h^-1, respectively.展开更多
基金supported by the National Key Project for Basic Research of China (973 Project) (No. 2005CB221400)
文摘Nickel and potassium co-modified β-Mo2C catalysts were prepared and used for CO hydrogenation reaction. The major products over β-Mo2C were C1-C4 hydrocarbons, only few alcohols were obtained. Addition of potassium resulted in remarkable selectivity shift from hydrocarbons to alcohols at the expense of CO conversion over β-Mo2C. Moreover, it was found that potassium enhanced the ability of chain propagation with a higher C2＋OH production. Modified by nickel,β-Mo2C showed a relatively high CO conversion, however, the products were similar to those of pure β-Mo2C. When co-modified by nickel and potassium,β-Mo2C exhibited high activity and selectivity towards mixed alcohols synthesis, and also the whole chain propagation to produce alcohols especially for the stage of C1 OH to C2OH was remarkably enhanced. It was concluded that the Ni and K had, to some extent, synergistic effect on CO conversion.
基金supported by the National Natural Science Foundation of China(No.22072015)the Foundation of Sichuan Department of Science and Technology(No.2017FZ0079).
文摘The advancement of cost-effective and selective electrocatalyst towards CO_(2) to CO conversion is crucial for renewable energy conversion and storage,thus to achieve carbon-neutral cycle in a sustainable manner.In this communication,we report that CujSb decorated Cu nanowire arrays on Cu foil act as a highly active and selective electrocatalyst for CO_(2) to CO conversion.In CO_(2)-saturated 0.1 M KHCO_(3),it achieves a high Faraday efficiency(FE)of 86.5%for CO,at-0.90 V vs.reversible hydrogen electrode(RHE).The H_(2)/CO ratio is tunable from 0.08:1 to 5.9:1 by adjusting the potential.It is worth noting that HCOO-product was totally suppressed on such catalyst,compared with Sb counterpart.The improving selectivity for CO could be attributed to the bimetallic effect and nanowire arrays structure.
基金supported by the National Natural Science Foundation of China(22378166)the Basic Research Program of Jiangsu and Jiangsu Basic Research Center for Synthetic Biology(BK20233003)+1 种基金the Fundamental Research Funds for the Central Universities(JUSRP622001)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX24_2583).
文摘Human activities and industrial emissions have markedly intensified the concentration of CO_(2)in the atmosphere,projected to reach 500 parts per million by 2045,thereby worsening global issues such as climate change and extreme weather events.To tackle these challenges,substantial efforts have been dedicated to developing efficient methods for converting the abundant and frequently underutilized one-carbon resource,such as CO_(2),to complex compounds.Currently,two main approaches exist to achieve this goal:chemical and biological methods.
文摘This research investigates the use of biochar derived from agricultural waste as a support material for Fe-based(Fe-Co-K)catalysts,with and without Zn,in CO and CO_(2)hydrogenation,benchmarking its performance against commercial activated carbon.Under semi-industrial Fischer-Tropsch conditions,biochar-supported catalysts,particularly the Zn-enhanced variant(ZFCK@C),delivered superior catalytic outcomes.The catalysts were prepared using ultrasound-assisted dissolution and incipient wetness methods and characterized using FTIR,XRD,BET,H_(2)-TPR,CO_(2)-TPD,XPS,and TEM.In CO hydrogenation at 340◦C and 20 bar,ZFCK@C achieved a remarkable 97%conversion,with 32%longer hydrocarbons selectivity(C_(5+)),39.6%olefins distribution(C_(5+)),an O/P ratio of 4.0,and 45.3%gasoline-range(C_(5)-C_(12))hydrocarbons distribution.For CO_(2)hydrogenation at 340◦C and 30 bar,the catalyst showed 40%conversion,low CH_(4)selectivity(6.1%),high C_(5+)selectivity(45%),38.7%olefins distribution(C_(5+)),an O/P ratio of 3.2,and 45.3%kerosene-range(C6-C16)hydrocarbons dis-tribution.Stability testing over 100 h demonstrated excellent durability with no significant deactivation or sintering,making the catalyst viable for extended industrial use.
基金supported by the Tianjin Municipal Science and Technology Commission(14JCZDJC37500)
文摘In this study, different methods were used to prepare MoO3/ZrO2 catalysts for sulfur resistant methanation reaction. It was found that MoO3/ZrO2 catalyst prepared by one-step co-precipitation method achieved high methanation performance. CO conversion could reach up to 90% on 25 wt% MoO3/ZrO2 catalyst, much higher than that on the conventional 25 wt% MoO3/Al2O3 catalyst. The Mo-based catalysts were characterized by XRF, XRD, Raman, BET, TEM and H2-TPR etc. It was found that MoO3 particles were highly dispersed on ZrO2 support for 25 wt% MoO3/ZrO2 catalyst prepared at 65-85℃ because of its relatively larger pore size, which contributed to a high CO conversion. Meanwhile, when MoO3 loading exceeded the monolayer coverage, the formed crystalline MoO3 and ZrM020g might block the micropores of the catalyst and make the methanation activity declined. These results are useful for preparing highly efficient catalyst for CO methanation process.
基金financially supported by the National Key R&D Program of China (No. 2017YFA0700104)the National Natural Science Foundation of China (Nos. 22071182, 21861001, 21931007 and21790052)+1 种基金the 111 Project of China (No. D17003)the Science&Technology Development Fund of Tianjin Education Commission for Higher Education (No. 2018KJ129)。
文摘Metal-organic frameworks(MOFs) as a type of crystalline heterogeneous catalysts have shown potential application in photocatalytic CO_(2)reduction.However,MOF catalysts with high efficiency and selectivity are still in pursuit.Herein,by a bimetallic strategy,the catalytic performance of a Co-MOF for photocatalytic CO_(2)reduction was enhanced.Specifically,the Co-MOF based on 4,5-dicarboxylic acid(H;IDC) and4,4’-bipydine(4,4’-bpy) can catalyze CO;reduction to CO,with high efficiency but relatively low selectivity.After replacement of 2/3 Co(Ⅱ) with Ni(Ⅱ) within Co-MOF,the resulted isostructural Co_(1)Ni_(2)-MOF not only retains high efficiency for photocatalytic CO_(2)reduction,but also shows enhanced CO selectivity.The CO evolution rate reaches 1160 μmol g^(-1)h^(-1)and the CO selectivity reaches as high as 94.6%.The enhanced photocatalytic CO_(2)reduction performance is supported by theoretical calculation results.This case demonstrates that bimetallic strategy is an effective mean to optimize the catalytic performance of MOF catalysts for photochemical CO_(2)reduction.
基金This work was supported by the Doctoral Foundation of China(No.20050251006).
文摘16.6%Co/γ-Al2O3 catalysts prepared by incipient wetness impregnation method were used for Fischer-Tropsch synthesis. The support was pre-treated with different concentration of NH4NO3 aqueous solution. The effect of support pre-treatment on the properties of support and performance of supportedcobalt-based catalysts was investigated. To treat the support with NH4NO3 aqueous solution enlarged the pore of γ-Al2O3, decreased the impurity Na2O content, and weakened the surface acidity of γ-Al2O3. The change in the properties of the support decreased the interaction between cobalt species and support, enhanced the CO hydrogenation rate and the C5＋ selectivity. For all catalysts, increasing the reaction temperature increased the CO hydrogenation rate or the CO conversion, slightly decreased the total hydrocarbon selectivity, and favored the formation of methane and light hydrocarbons, while the chain growth probability decreased. For 16.6%Co/γ-Al2O3 catalysts, prepared with the support treated with 100 g/L NH4NO3 aqueous solution, the CO conversion, the CH4 selectivity, and the C5＋ selectivity were 83.13%, 6.86% and 82.75% respectively, and the chain growth probability was 0.83 under the condition of 493 K, 1.5 MPa, 500 h-1 and the molar ratio of H2 to CO being 2.0 in feed.
基金funding support from the National Natural Science Foundation of China (51722404, 51674177, 91845113 and 51804221)the “1000-Youth Talents Plan”+3 种基金the Fundamental Research Funds for the Central Universities (2042017kf0200)National Key R&D Program of China (2018YFE0201703)the China Postdoctoral Science Foundation (2018M642906 and 2019T120684)Hubei Provincial Natural Science Foundation of China (2019CFA065)。
文摘Structural and compositional design of core-shell structure is an effective strategy towards enhanced catalysis.Herein,amorphous MnO2 nanosheets and K+-intercalated layered MnO2 nanosheets are controllably assembled over Fe2O3 spindles,in which the MnO2 nanosheets are perpendicularly anchored to the surface of Fe2O3.Such a core shell structure contributes to a high specific surface area and abundant pore channels on the surface of catalysts.In addition,the existence of K+provides large numbers of basic sites and restrains the formation of unpleasant(Fe1-xMnx)3O4.Benefiting from the merits in structure and composition,CO adsorption is enhanced and remaining time of intermediates is prolonged on the surfaces of catalysts during the Fischer–Tropsch synthesis(FTS),facilitating to the formation of active iron carbides and C–C coupling reactions.Resultantly,the Fe2O3@K+-Mn O2 shows both a high CO conversion of 82.3%and a high C5+ selectivity of 73.1%.The present study provides structural and compositional rationales on design high-performance catalysts towards FTS.
文摘Two K/Mn-MgO supported catalysts were prepared by Fe（CO）5 and Fe（NO3）3 as precursor respectively. The obtained Fe-K/Mn-MgO catalysts were tested for CO hydrogenation to light alkenes and characterized by X-ray powder diffraction （XRD）, X-ray photoelectron spectra （XPS）, H2 temperature-programmed reduction （H2-TPR）, H2 CO and CO2 temperature-programmed desorption （H2, CO/CO2-TPD） and transmission electron microscope （TEM） The results indicated that the catalyst with 10 wt% Fe loading prepared by Fe（CO）5 as precursor showed better performance in syngas to light alkenes than ones obtained from Fe（NO3）3 as precursor, where the CO conversion was 62.50% and the selectivity was 55.95% at 350 ℃, 1.5 MPa and 1000 h^-1, respectively.
