With the rapid development of economy,the consumption of fossil fuels and excessive emissions of carbon dioxide(CO_(2))have led to many environmental issues.The thermocatalytic conversion of CO_(2) to high value‐adde...With the rapid development of economy,the consumption of fossil fuels and excessive emissions of carbon dioxide(CO_(2))have led to many environmental issues.The thermocatalytic conversion of CO_(2) to high value‐added chemicals is an effective strategy to meet the need of carbon neutralization.Among them,CO_(2) hydrogenation to light olefins has been well researched so that the selectivity of desired products can exceed the Anderson–Schulz–Flory(ASF)distribution to acquire an extremely high yield.However,although huge progress has been made in CO_(2) hydrogenation to produce long‐chain α‐olefins based on Fe catalysts as well,designing efficient catalysts with promoted C‐O dissociation and C‐C coupling remains challenging.In addition,ASF distribution restrains the selectivity of desired long‐chain products,whereas the approaches to breaking it still face issues.In this review,we focus on the design of Fe‐based catalysts for the synthesis of long‐chainα‐olefins through CO_(2) hydrogenation.We have summarized and analyzed the reaction mechanism,design of catalysts,structure–activity relationship,interaction between Fe and promoters,and strategies to break the ASF distribution.At the same time,the issues faced by CO_(2) hydrogenation to long‐chain α‐olefins are proposed and the possible future solutions are prospected.This review aims to provide a recent development on the design of Fe‐based catalysts for CO_(2) hydrogenation to long‐chain α‐olefins while considering the ASF distribution.展开更多
A series of iron(Fe)modified CuO-ZnO-ZrO_(2)-Al_(2)O_(3)(CZZA)catalysts,with various Fe loadings,were prepared using a co-precipitation method.A bifunctional catalyst,consisting of Fe-modified CZZA and HZSM-5,was stud...A series of iron(Fe)modified CuO-ZnO-ZrO_(2)-Al_(2)O_(3)(CZZA)catalysts,with various Fe loadings,were prepared using a co-precipitation method.A bifunctional catalyst,consisting of Fe-modified CZZA and HZSM-5,was studied for dimethyl ether(DME)synthesis via CO_(2)hydrogenation.The effects of Fe loading,reaction temperature,reaction pressure,space velocity,and concentrations of precursor for the synthesis of the Fe-modified CZZA catalyst on the catalytic activity of DME synthesis were investigated.Long-term stability tests showed that Fe modification of the CZZA catalyst improved the catalyst stability for DME synthesis via CO_(2)hydrogenation.The activity loss,in terms of DME yield,was significantly reduced from 4.2%to 1.4%in a 100 h run of reaction,when the Fe loading amount was 0.5(molar ratio of Fe to Cu).An analysis of hydrogen temperature programmed reduction revealed that the introduction of Fe improved the reducibility of the catalysts,due to assisted adsorption of H2 on iron oxide.The good stability of Femodified CZZA catalysts in the DME formation was most likely attributed to oxygen spillover that was introduced by the addition of iron oxide.This could have inhibited the oxidation of the Cu surface and enhanced the thermal stability of copper during long-term reactions.展开更多
A novel nanosized amorphous Ru-Fe-B/ZrO2 alloy catalyst for benzene selective hydrogenation to cyclohexene was investigated. The superior properties of this catalyst were attributed to the combination of the nanosize ...A novel nanosized amorphous Ru-Fe-B/ZrO2 alloy catalyst for benzene selective hydrogenation to cyclohexene was investigated. The superior properties of this catalyst were attributed to the combination of the nanosize and the amorphous character as well as to its textural character. In addition, the concentration of zinc ions, the content of ZrO2 in the slurry, and the pretreatment of the catalyst were found to be effective in improving the activity and the selectivity of the catalyst.展开更多
The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support,...The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one （ZrO2-1） was obtained from the commercial ZrO2 and the other （ZrO2-2） was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.展开更多
We report Ni/LaHA@ZrO2catalysts prepared by a facile modified successive adsorption and reaction method for CO methanation.N2adsorption,X‐ray diffraction,transmission electron microscopy,scanning electron microscopy,...We report Ni/LaHA@ZrO2catalysts prepared by a facile modified successive adsorption and reaction method for CO methanation.N2adsorption,X‐ray diffraction,transmission electron microscopy,scanning electron microscopy,thermogravimetric analysis,H2temperature‐programmed reduction,H2temperature‐programmed desorption,X‐ray photoelectron spectroscopy,thermogravimetric analysis,and inductively coupled plasma atomic emission spectrometry were used to characterize the samples.The results indicated that the ZrO2nanoparticles were distributed over the surface of the Ni/LaHA@ZrO2catalyst and even partially covered some Ni particles,resulting in the coating exerting a confinement effect.The excess ZrO2had an adverse effect on the enhancement of CO conversion because of the coverage of the surface Ni particles;however,the Ni/LaHA@ZrO2catalyst displayed much higher CH4selectivity than Ni/LaHA because of the activation of the byproduct CO2molecules by ZrO2species.Therefore,even though20Ni/LaHA@ZrO2‐5exhibited similar CO conversion as20Ni/LaHA,the use of the former resulted in a higher CH4yield than the use of the latter.A107‐h‐lifetime test revealed that the Ni/LaHA@ZrO2catalyst was highly stable with superior anti‐sintering and anti‐coking properties because of its coating structure and the promoter effect of ZrO2.展开更多
A 60%Fe/Al_2O_3 catalyst was prepared by the co-precipitation method.It was reduced by H_2 to produce metallic Fe,which was then sulfided by CS_2 to Fe_(0.96) S and Fe_3S_4 or phosphided by triphenylphosphine(PPh3) in...A 60%Fe/Al_2O_3 catalyst was prepared by the co-precipitation method.It was reduced by H_2 to produce metallic Fe,which was then sulfided by CS_2 to Fe_(0.96) S and Fe_3S_4 or phosphided by triphenylphosphine(PPh3) in liquid phases to Fe2 P and Fe P.It was found that the iron sulfides(Fe0.96 S and Fe_3S_4) exhibited the low activity for the hydrodesulfurization(HDS) reactions.The HDS activity was also low on the Fe(metal)/Al_2O_3 and Fe_2 P/Al_2O_3 catalysts since they were converted into Fe0.96 S and Fe_3S_4 during the HDS reactions.In contrast,the FeP/Al_2O_3 was found to be stable and active for the HDS reactions.In particular,Fe P/Al_2O_3 possessed significantly smaller Fe P particles than Fe P/C,leading to the significant higher HDS activity of FeP/Al_2O_3 than Fe P/C.展开更多
Amorphous Ni-B/ZrO2 catalysts were prepared by coprecipitation-chemical reduction with KBH4 aqueous solution,and various crystalline phase ZrO2(amorphous-ZrO2,tetragonal-ZrO2 and monoclinic-ZrO2) supported Ni-B cataly...Amorphous Ni-B/ZrO2 catalysts were prepared by coprecipitation-chemical reduction with KBH4 aqueous solution,and various crystalline phase ZrO2(amorphous-ZrO2,tetragonal-ZrO2 and monoclinic-ZrO2) supported Ni-B catalysts were obtained by thermal treatment in 5%H2-N2 stream at different temperature.The effect of ZrO2 polymorphs and the treatment temperature on the catalytic performance for the CO selective methanation were investigated,and the catalysts were characterized by N2 physisorption,Powder X-ray diffraction(XRD), Temperature-Programmed Desorption(CO-TPD and H2-TPD),and Differential Scanning Calorimeter(DSC).The treatment temperature affected strongly the crystalline structure of ZrO2,and the CO methanation activity and selectivity of the Ni-B/ZrO2 catalysts were significantly influenced by the crystalline phase of ZrO2.Of the three forms of ZrO2 polymorphs(amorphou-ZrO2,tetragonal-ZrO2 and monoclinic-ZrO2),the amorphous-ZrO2 supported nickle catalyst showed highest CO methanation activity,attributing in large part to the largest specific surface area and the optimum CO/H2 absorption intensity of the Ni-B/amorphous-ZrO2 catalyst.展开更多
This work reports the enhancing effect of a highly cost effective and efficient metal, Fe, incorporation to Co or Ni based Mo/Al2O3 catalysts in the oxidative desulfurization （ODS） of dibenzothiophene （DBT） using ...This work reports the enhancing effect of a highly cost effective and efficient metal, Fe, incorporation to Co or Ni based Mo/Al2O3 catalysts in the oxidative desulfurization （ODS） of dibenzothiophene （DBT） using H2O2 and formic acid as oxidants. The influence of operating parameters i.e. reaction time, catalyst dose, reaction temperature and oxidant amount on oxidation process was investigated. Results revealed that 99% DBT conversion was achieved at 60℃ and 150 min reaction time over Fe-Ni-Mo/Al2O3. Fe tremendously enhanced the ODS activity of Co or Ni based Mo/Al2O3 catalysts following the activity order：Fe-Ni-Mo/Al2O3 〉 Fe-Co-Mo/Al2O3 〉 Ni-Mo/Al2O3 〉 Co-Mo/Al2O3, while H2O2 exhibited higher oxidation activity than formic acid over all catalyst systems. Insight about the surface morphology and textural properties of fresh and spent catalysts were achieved using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive X-ray （EDX） analysis, Atomic Absorption Spectroscopy （AAS） and BET surface area analysis, which helped in the interpretation of experimental data. The present study can be deemed as an effective approach on industrial level for ODS of fuel oils crediting to its high efficiency, low process/catalyst cost, safety and mild operating condition.展开更多
A solid superacid catalyst Pt-SO42-/ZrO2-A12O3 for n-pentane isomerization, was prepared by incipient-wetness impregnation. Preparetion conditions, namely, calcination temperature, concentration of sulfuric acid solut...A solid superacid catalyst Pt-SO42-/ZrO2-A12O3 for n-pentane isomerization, was prepared by incipient-wetness impregnation. Preparetion conditions, namely, calcination temperature, concentration of sulfuric acid solution used in impregnation and Al2O3 concentration, were varied to investigate the effects on catalytic performance of Pt-SO42-/ZrO2-A12O3. The results showed that the PtSZA catalyst exhibited excellent catalytic performance for n-pentane isomerization. Under optimized preparation conditions of calcination temperature of 650°C, reaction time for 3 h, concentration of sulfuric acid solution for 0.5 mol/L, 30% of Al2O3 concentration and 0.3% of Pt concentration, the n-pentane conversion and isopentane selectivity of Pt-SO42-/ZrO2-A12O3 could reach up to 62.17% and 91.60%, respectively.展开更多
Fe-based catalysts are efficient systems for CO_(2)conversion via reverse water-gas shift(rWGS)reaction.Nevertheless,the nature of the active phase,namely metallic iron,iron oxide or iron carbide remains a subject of ...Fe-based catalysts are efficient systems for CO_(2)conversion via reverse water-gas shift(rWGS)reaction.Nevertheless,the nature of the active phase,namely metallic iron,iron oxide or iron carbide remains a subject of debate which our paper is meant to close.Fe0 is a much better catalyst for the rWGS than Fe_(3)C.The activity of Fe0 can be promoted by the addition of Cs and Cu whose presence hinders iron carburisation while favouring both higher conversion and enhanced selectivity.When the samples are aged in the rWGS reaction mixture during stability test a new phase appear:Fe_(5)C_(2),resulting in a more active but less selective catalysts than Fe0 for the rWGS reaction.Hence our results indicate that we could potentially achieve an optimal activity/selective balance upon finely tuning the proportion Fe/Fe_(5)C_(2).Beyond the fundamental information concerning active phase we have observed the presence of advanced Fischer-Tropsch-like products at ambient pressure opening new opportunities for the design of hybrid rWGS/Fischer-Tropsch systems.展开更多
基金supported by the CNPC Innovation Found(2021DQ02‐0702).
文摘With the rapid development of economy,the consumption of fossil fuels and excessive emissions of carbon dioxide(CO_(2))have led to many environmental issues.The thermocatalytic conversion of CO_(2) to high value‐added chemicals is an effective strategy to meet the need of carbon neutralization.Among them,CO_(2) hydrogenation to light olefins has been well researched so that the selectivity of desired products can exceed the Anderson–Schulz–Flory(ASF)distribution to acquire an extremely high yield.However,although huge progress has been made in CO_(2) hydrogenation to produce long‐chain α‐olefins based on Fe catalysts as well,designing efficient catalysts with promoted C‐O dissociation and C‐C coupling remains challenging.In addition,ASF distribution restrains the selectivity of desired long‐chain products,whereas the approaches to breaking it still face issues.In this review,we focus on the design of Fe‐based catalysts for the synthesis of long‐chainα‐olefins through CO_(2) hydrogenation.We have summarized and analyzed the reaction mechanism,design of catalysts,structure–activity relationship,interaction between Fe and promoters,and strategies to break the ASF distribution.At the same time,the issues faced by CO_(2) hydrogenation to long‐chain α‐olefins are proposed and the possible future solutions are prospected.This review aims to provide a recent development on the design of Fe‐based catalysts for CO_(2) hydrogenation to long‐chain α‐olefins while considering the ASF distribution.
基金supported by the U.S.Department of Energy through contract DE-AR0000806。
文摘A series of iron(Fe)modified CuO-ZnO-ZrO_(2)-Al_(2)O_(3)(CZZA)catalysts,with various Fe loadings,were prepared using a co-precipitation method.A bifunctional catalyst,consisting of Fe-modified CZZA and HZSM-5,was studied for dimethyl ether(DME)synthesis via CO_(2)hydrogenation.The effects of Fe loading,reaction temperature,reaction pressure,space velocity,and concentrations of precursor for the synthesis of the Fe-modified CZZA catalyst on the catalytic activity of DME synthesis were investigated.Long-term stability tests showed that Fe modification of the CZZA catalyst improved the catalyst stability for DME synthesis via CO_(2)hydrogenation.The activity loss,in terms of DME yield,was significantly reduced from 4.2%to 1.4%in a 100 h run of reaction,when the Fe loading amount was 0.5(molar ratio of Fe to Cu).An analysis of hydrogen temperature programmed reduction revealed that the introduction of Fe improved the reducibility of the catalysts,due to assisted adsorption of H2 on iron oxide.The good stability of Femodified CZZA catalysts in the DME formation was most likely attributed to oxygen spillover that was introduced by the addition of iron oxide.This could have inhibited the oxidation of the Cu surface and enhanced the thermal stability of copper during long-term reactions.
文摘A novel nanosized amorphous Ru-Fe-B/ZrO2 alloy catalyst for benzene selective hydrogenation to cyclohexene was investigated. The superior properties of this catalyst were attributed to the combination of the nanosize and the amorphous character as well as to its textural character. In addition, the concentration of zinc ions, the content of ZrO2 in the slurry, and the pretreatment of the catalyst were found to be effective in improving the activity and the selectivity of the catalyst.
文摘The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one （ZrO2-1） was obtained from the commercial ZrO2 and the other （ZrO2-2） was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.
基金supported by the National Natural Science Foundation of China (21606146)Natural Science Foundation of Shandong Province (ZR2016BB17,2016ZRB01037)+3 种基金Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents (2016RCJJ005,2016RCJJ006)Government Sponsored Visiting Scholar Foundation of Shandong University of Science and Technology (2016)Qingdao Postdoctoral Applied Research Project (2015202)China National Coal Association Science and Technology Research Program (MTKJ2016-266)~~
文摘We report Ni/LaHA@ZrO2catalysts prepared by a facile modified successive adsorption and reaction method for CO methanation.N2adsorption,X‐ray diffraction,transmission electron microscopy,scanning electron microscopy,thermogravimetric analysis,H2temperature‐programmed reduction,H2temperature‐programmed desorption,X‐ray photoelectron spectroscopy,thermogravimetric analysis,and inductively coupled plasma atomic emission spectrometry were used to characterize the samples.The results indicated that the ZrO2nanoparticles were distributed over the surface of the Ni/LaHA@ZrO2catalyst and even partially covered some Ni particles,resulting in the coating exerting a confinement effect.The excess ZrO2had an adverse effect on the enhancement of CO conversion because of the coverage of the surface Ni particles;however,the Ni/LaHA@ZrO2catalyst displayed much higher CH4selectivity than Ni/LaHA because of the activation of the byproduct CO2molecules by ZrO2species.Therefore,even though20Ni/LaHA@ZrO2‐5exhibited similar CO conversion as20Ni/LaHA,the use of the former resulted in a higher CH4yield than the use of the latter.A107‐h‐lifetime test revealed that the Ni/LaHA@ZrO2catalyst was highly stable with superior anti‐sintering and anti‐coking properties because of its coating structure and the promoter effect of ZrO2.
基金Financial supports from the NSFC-DFG (21761132006),NSFC (21773108)fundamental research funds for central universities are acknowledged
文摘A 60%Fe/Al_2O_3 catalyst was prepared by the co-precipitation method.It was reduced by H_2 to produce metallic Fe,which was then sulfided by CS_2 to Fe_(0.96) S and Fe_3S_4 or phosphided by triphenylphosphine(PPh3) in liquid phases to Fe2 P and Fe P.It was found that the iron sulfides(Fe0.96 S and Fe_3S_4) exhibited the low activity for the hydrodesulfurization(HDS) reactions.The HDS activity was also low on the Fe(metal)/Al_2O_3 and Fe_2 P/Al_2O_3 catalysts since they were converted into Fe0.96 S and Fe_3S_4 during the HDS reactions.In contrast,the FeP/Al_2O_3 was found to be stable and active for the HDS reactions.In particular,Fe P/Al_2O_3 possessed significantly smaller Fe P particles than Fe P/C,leading to the significant higher HDS activity of FeP/Al_2O_3 than Fe P/C.
基金Supported by the National Natural Science Foundation of China(21076047)the Natural Science Foundation of Zhongkai University of Agriculture and Engineering(G3100026)
文摘Amorphous Ni-B/ZrO2 catalysts were prepared by coprecipitation-chemical reduction with KBH4 aqueous solution,and various crystalline phase ZrO2(amorphous-ZrO2,tetragonal-ZrO2 and monoclinic-ZrO2) supported Ni-B catalysts were obtained by thermal treatment in 5%H2-N2 stream at different temperature.The effect of ZrO2 polymorphs and the treatment temperature on the catalytic performance for the CO selective methanation were investigated,and the catalysts were characterized by N2 physisorption,Powder X-ray diffraction(XRD), Temperature-Programmed Desorption(CO-TPD and H2-TPD),and Differential Scanning Calorimeter(DSC).The treatment temperature affected strongly the crystalline structure of ZrO2,and the CO methanation activity and selectivity of the Ni-B/ZrO2 catalysts were significantly influenced by the crystalline phase of ZrO2.Of the three forms of ZrO2 polymorphs(amorphou-ZrO2,tetragonal-ZrO2 and monoclinic-ZrO2),the amorphous-ZrO2 supported nickle catalyst showed highest CO methanation activity,attributing in large part to the largest specific surface area and the optimum CO/H2 absorption intensity of the Ni-B/amorphous-ZrO2 catalyst.
文摘This work reports the enhancing effect of a highly cost effective and efficient metal, Fe, incorporation to Co or Ni based Mo/Al2O3 catalysts in the oxidative desulfurization （ODS） of dibenzothiophene （DBT） using H2O2 and formic acid as oxidants. The influence of operating parameters i.e. reaction time, catalyst dose, reaction temperature and oxidant amount on oxidation process was investigated. Results revealed that 99% DBT conversion was achieved at 60℃ and 150 min reaction time over Fe-Ni-Mo/Al2O3. Fe tremendously enhanced the ODS activity of Co or Ni based Mo/Al2O3 catalysts following the activity order：Fe-Ni-Mo/Al2O3 〉 Fe-Co-Mo/Al2O3 〉 Ni-Mo/Al2O3 〉 Co-Mo/Al2O3, while H2O2 exhibited higher oxidation activity than formic acid over all catalyst systems. Insight about the surface morphology and textural properties of fresh and spent catalysts were achieved using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive X-ray （EDX） analysis, Atomic Absorption Spectroscopy （AAS） and BET surface area analysis, which helped in the interpretation of experimental data. The present study can be deemed as an effective approach on industrial level for ODS of fuel oils crediting to its high efficiency, low process/catalyst cost, safety and mild operating condition.
文摘A solid superacid catalyst Pt-SO42-/ZrO2-A12O3 for n-pentane isomerization, was prepared by incipient-wetness impregnation. Preparetion conditions, namely, calcination temperature, concentration of sulfuric acid solution used in impregnation and Al2O3 concentration, were varied to investigate the effects on catalytic performance of Pt-SO42-/ZrO2-A12O3. The results showed that the PtSZA catalyst exhibited excellent catalytic performance for n-pentane isomerization. Under optimized preparation conditions of calcination temperature of 650°C, reaction time for 3 h, concentration of sulfuric acid solution for 0.5 mol/L, 30% of Al2O3 concentration and 0.3% of Pt concentration, the n-pentane conversion and isopentane selectivity of Pt-SO42-/ZrO2-A12O3 could reach up to 62.17% and 91.60%, respectively.
基金provided by the Royal Society Research Grant RSGR1180353partially sponsored by the CO2Chem UK through the Engineering and Physical Sciences Research Council(EPSRC)grant EP/P026435/1the Spanish Ministry of Science and Innovation through the projects RYC2018-024387-I and PID2019-108502RJ-I00.
文摘Fe-based catalysts are efficient systems for CO_(2)conversion via reverse water-gas shift(rWGS)reaction.Nevertheless,the nature of the active phase,namely metallic iron,iron oxide or iron carbide remains a subject of debate which our paper is meant to close.Fe0 is a much better catalyst for the rWGS than Fe_(3)C.The activity of Fe0 can be promoted by the addition of Cs and Cu whose presence hinders iron carburisation while favouring both higher conversion and enhanced selectivity.When the samples are aged in the rWGS reaction mixture during stability test a new phase appear:Fe_(5)C_(2),resulting in a more active but less selective catalysts than Fe0 for the rWGS reaction.Hence our results indicate that we could potentially achieve an optimal activity/selective balance upon finely tuning the proportion Fe/Fe_(5)C_(2).Beyond the fundamental information concerning active phase we have observed the presence of advanced Fischer-Tropsch-like products at ambient pressure opening new opportunities for the design of hybrid rWGS/Fischer-Tropsch systems.
