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Iron-based Catalysts Catalyzing Isoprene Polymerization:The Effect of Conjugated Groups in Cyanide-containing Electron Donors 认领 引用
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作者 Yao Liu Yao-Guang Liu +7 位作者 Jun-Xin Xu Qi Yang Wen-Peng Zhao Liang Fang Xiu-Juan Wang Heng Liu Chun-Yu Zhang Xue-Quan Zhang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2026年第5期1502-1512,I0016,共11页
In this study,the coordination pathways and decomposition behavior of azo-containing dicyano compounds within Fe(acac)3/AliBu3/donor ternary catalyst systems were systematically investigated via in situ Raman spectros... In this study,the coordination pathways and decomposition behavior of azo-containing dicyano compounds within Fe(acac)3/AliBu3/donor ternary catalyst systems were systematically investigated via in situ Raman spectroscopy.Additionally,the modulating effect of conjugated moieties on the coordination interaction between cyanide groups and Fe ions was examined in detail.Experimental results demonstrate that isoprene polymerization catalyzed by azodicyanide mediated Fe-based catalytic systems proceeds via a coordination polymerization mechanism.Notably,the azo group does not directly participate in the coordination process;instead,it exerts a regulatory influence on the coordination capacity of the cyano group.Although thermal decomposition of the azo group occurs at elevated temperatures,it fails to initiate free radical polymerization of the isoprene monomer.Conjugated moieties including azo,vinyl,and benzene rings exert distinct impacts on the cyanide group.As electron-donating species,their Raman spectral characteristics reflect varying influences on cyanide coordination behavior.Density functional theory(DFT)calculations demonstrate that AIBN with azo groups as the conjugated moiety exhibits the most negative Gibbs free energy(ΔG°=–222.71 kcal·mol–1)for the coordination reaction with Fe2+,indicating that the cyano groups in the azo-containing compound possess the strongest coordination capability with Fe2+.The coordination effects of conjugated groups on the cyanide center follow the sequence:azo>carbon-carbon double bond>benzene ring,where azo groups show the most significant coordination enhancement.These theoretical findings are consistent with the observed polymerization activity,suggesting that rational design of electron donors can be guided by theoretical calculations. 展开更多
关键词 Iron-based catalysts Polyisoprene Azo group Raman spectroscopy Density functional theory(DFT)
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Iron-based catalysts for NOx reduction:Reaction mechanism and anti-poisoning strategies 认领 引用
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作者 Zaisheng Jin Fuli Wang +6 位作者 Yongjie Shen Xiaonan Hu Yanqi Chen Jin Zhang Ming Xie Penglu Wang Dengsong Zhang 《Chinese Chemical Letters》 SCIE CAS CSCD 2026年第4期232-245,共14页
Iron-based metal oxide catalysts are widely used for selective catalytic reduction(SCR)of NOx with NH3 due to their excellent catalytic performance at medium and high temperatures,high nitrogen selectivity,robus... Iron-based metal oxide catalysts are widely used for selective catalytic reduction(SCR)of NOx with NH3 due to their excellent catalytic performance at medium and high temperatures,high nitrogen selectivity,robust resistance to sulfur dioxide poisoning,environmental sustainability and cost effectiveness.However,several challenges including sub-optimal low-temperature catalytic activity,narrow operating temperature range,poor resistance to alkali/alkaline earth metal poisoning,as well as insufficient thermal stability and H2O/SO2 resistance always hinder the further application of iron-based metal oxide catalysts,which is in urgent need of further improvement in practical applications.This review provides a comprehensive overview of the development,applications and challenges associated with different types of iron-based metal oxide catalysts and suggests corresponding modification strategies to address the as-mentioned issues.Iron oxide catalysts can promote low-temperature catalytic performance by adjusting crystal structures and exposing specific crystal faces;however,their thermal stability and resistance to SO2/H2O and alkali metals still have substantial room for improvement.Iron-based composite metal oxide catalysts can effectively increase the resistance to SO2/H2O by coupling multiple metals and modulating adjacent electronic sites.Iron-based acidic salt catalysts greatly enhance the resistance to alkali metal poisoning by enriching the surface acid sites and providing sacrificial sites.Supported iron-based metal oxide catalysts can significantly improve both catalytic performance and resistance by modulating reaction pathways and constructing core-shell structures.This review clarifies the important direction of further research on iron-based metal oxide catalysts,and provides scientific basis and design ideas for the development and application of high-efficiency low-temperature NOx reduction catalysts. 展开更多
关键词 Nitric oxide Selective catalytic reduction Iron-based catalysts Anti-poisoning Environmental catalysis
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Atmosphere-Regulated Pyrolysis Switches ORR Pathway on Iron-Based Catalyst for H2O2 Synthesis and Zn-Air Batteries 认领 引用
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作者 Songhan Hu Mingyuan Ma +2 位作者 Xinxin Xu Kai Wang Qiang Wang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2026年第3期209-218,共10页
Developing simple methods to achieve flexible regulation of oxygen reduction reaction(ORR)selectivity is essential for sustainable energy technologies,yet remains challenging.An effective strategy for directing ORR se... Developing simple methods to achieve flexible regulation of oxygen reduction reaction(ORR)selectivity is essential for sustainable energy technologies,yet remains challenging.An effective strategy for directing ORR selectivity through pyrolysis atmosphere is proposed using[Fe(TPDC)2(BIB)2]n(FeMOF,TPDC=3,4-thiophenedicarboxylic acid;BIB=1,4-bis(3-imidazolyl)-benzene)as the precursor.Notably,Fe2O3derived from air pyrolysis exhibits high two-electron(2e-)ORR selectivity for hydrogen peroxide(H2O2)production,achieving a rate of 0.99 mol g⁻¹h⁻¹,whereas Fe and Fe3C encapsulated in nitrogen-doped carbon nanotubes(Fe/Fe3C@NCNTs)from N2-pyrolysis demonstrates high-efficiency four-electron(4e-)ORR selectivity(E1/2=0.92 V vs.RHE),exceeding Pt/C.Fe/Fe3C@NCNT-based cathode enabled zinc-air battery(ZAB)to achieve exceptional peak power density and remarkable cycle stability.Theoretical calculations indicate that the binding strength of the*OOH intermediate governs ORR selectivity.Simple atmosphere adjustment during the pyrolysis process enables on-demand optimization of electrocatalyst ORR selectivity,demonstrating MOF potential in electrocatalysis and providing new perspectives for designing low-cost,efficient non-noble metal catalysts. 展开更多
关键词 hydrogen peroxide iron-based electrocatalyst oxygen reduction reaction oxygen reduction reaction selectivity zinc-air battery
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Manganese promoter hinders carbon permeation on iron-based catalyst surfaces:A first-principles study 认领 引用
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作者 YANG Tao MA Huan LIU Xingchen 《燃料化学学报（中英文）》 EI CAS CSCD 北大核心 2026年第7期170-193,共24页
Fe-Mn catalysts have garnered considerable attention for industrial applications in the Fischer-Tropsch synthesis(FTS)process.Carbon adsorption and permeation on catalyst surfaces constitute critical elementary steps ... Fe-Mn catalysts have garnered considerable attention for industrial applications in the Fischer-Tropsch synthesis(FTS)process.Carbon adsorption and permeation on catalyst surfaces constitute critical elementary steps in the in situ formation of active phases in iron-based FTS catalysts.Herein,density functional theory(DFT)calculations are employed to systematically investigate the atomistic structures,thermodynamic stabilities,and electronic properties of carbon-deposited Fe-Mn alloy surfaces at the early stage of carburization.These Fe-Mn alloy surfaces show distinct thermodynamic sensitivity to carbon atoms adsorbed on the surface and permeating into the interstitial sites.By combining DFT with minima-hopping structural searches,we demonstrate that the initial stage of carbon permeation cannot trigger the reconstruction of surface regions to form surface iron carbide phases.The addition of manganese thermodynamically hinders the carbon permeation process.Although deposited C atoms modulate the electronic structure of metals,the presence of manganese retards the shift of d-band centers of metals to those of the bulk iron carbide phases.Our study provides an atomic-scale insight into the in situ evolution of Fe-Mn catalyst surfaces during the carbon deposition process and indicates that the manganese promoter has a noticeable effect on carbon permeation. 展开更多
关键词 Fe-Mn catalyst carbon adsorption and permeation DFT thermodynamic stability electronic structure
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Towards advanced removal of organics in persulfate solution by heterogeneous iron-based catalyst:A review 认领 引用 被引量：3
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作者 Baihui Cui Tingting Tian +5 位作者 Luchun Duan Hongwei Rong Zhihua Chen Shiyi Luo Dabin Guo Ravi Naidu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第12期163-175,共13页
Heterogeneous iron-based catalysts have drawn increasing attention in the advanced oxidation of persulfates due to their abundance in nature,the lack of secondary pollution to the environment,and their low cost over t... Heterogeneous iron-based catalysts have drawn increasing attention in the advanced oxidation of persulfates due to their abundance in nature,the lack of secondary pollution to the environment,and their low cost over the last a few years.In this paper,the latest progress in the research on the activation of persulfate by heterogeneous iron-based catalysts is reviewed from two aspects,in terms of synthesized catalysts(Fe0,Fe2O3,Fe3O4,FeOOH)and natural iron ore catalysts(pyrite,magnetite,hematite,siderite,goethite,ferrohydrite,ilmenite and lepidocrocite)focusing on efforts made to improve the performance of catalysts.The advantages and disadvantages of the synthesized catalysts and natural iron ore were summarized.Particular interests were paid to the activation mechanisms in the catalyst/PS/pollutant system for removal of organic pollutants.Future research challenges in the context of field application were also discussed. 展开更多
关键词 Activated persulfate Iron-based catalysts Iron ore-based catalysts Aactive free radicals Organic pollutants Heterogeneous catalysts
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A critical review towards the causes of the iron-based catalysts deactivation mechanisms in the selective oxidation of hydrogen sulfide to elemental sulfur from biogas 认领 引用 被引量：2
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作者 Mostafa Tarek Janaina S.Santos +4 位作者 Victor Márquez Mohammad Fereidooni Mohammad Yazdanpanah Supareak Praserthdam Piyasan Praserthdam 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期388-411,I0010,共24页
Hydrogen sulfide(H2S) not only presents significant environmental concerns but also induces severe corrosion in industrial equipment,even at low concentrations.Among various technologies,the selective oxidation of ... Hydrogen sulfide(H2S) not only presents significant environmental concerns but also induces severe corrosion in industrial equipment,even at low concentrations.Among various technologies,the selective oxidation of hydrogen sulfide(SOH2S) to elemental sulfur(S) has emerged as a sustainable and environmentally friendly solution.Due to its unique properties,iron oxide has been extensively investigated as a catalyst for SOH2S;however,rapid deactivation has remained a significant drawback.The causes of iron oxide-based catalysts deactivation mechanisms in SOH2S,including sulfur or sulfate deposition,the transformation of iron species,sintering and excessive oxygen vacancy formation,and active site loss,are thoroughly examined in this review.By focusing on the deactivation mechanisms,this review aims to provide valuable insights into enhancing the stability and efficiency of iron-based catalysts for SOH2S. 展开更多
关键词 Selective oxidation of H2S Iron-based Catalysts Mechanism of deactivation Sulfur or sulfate deposition Transformation of iron species Sintering SDG 7
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Effect of Al_2O_3 Binder on the Precipitated Iron-Based Catalysts for Fischer-Tropsch Synthesis 认领 引用 被引量：9
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作者 Hai-Jun Wan Bao-Shan Wu +4 位作者 Xia An Ting-Zhen Li Zhi-Chao Tao Hong-Wei Xiang Yong-Wang Li 《Journal of Natural Gas Chemistry》 2007年第2期130-138,共9页
A series of iron-based Fischer-Tropsch synthesis （FTS） catalysts incorporated with Al2O3 binder were prepared by the combination of co-precipitation and spray drying technology. The catalyst samples were characteriz... A series of iron-based Fischer-Tropsch synthesis （FTS） catalysts incorporated with Al2O3 binder were prepared by the combination of co-precipitation and spray drying technology. The catalyst samples were characterized by using N2 physical adsorption, temperature-programmed reduction/desorption （TPR/TPD） and MSssbauer effect spectroscopy （MES） methods. The characterization results indicated that the BET surface area increases with increasing Al2O3 content and passes through a maximum at the Al2O3/Fe ratio of 10/100 （weight basis）. After the point, it decreases with further increase in Al2O3 content. The incorporation of Al2O3 binder was found to weaken the surface basicity and suppress the reduction and carburization of iron-based catalysts probably due to the strong K-Al2O3 and Fe-Al2O3 interactions. Furthermore, the H2 adsorption ability of the catalysts is enhanced with increasing Al2O3 content. The FTS performances of the catalysts were tested in a slurry-phase continuously stirred tank reactor （CSTR） under the reaction conditions of 260 ℃, 1.5 MPa, 1000 h^-1 and molar ratio of H2/CO 0.67 for 200 h. The results showed that the addition of small amounts of Al2O3 affects the activity of iron-based catalysts to a little extent. However, with further increase of Al2O3 content, the FTS activity and water gas shift reaction （WGS） activity are decreased severely. The addition of appropriate Al2O3 do not affect the product selectivity, but the catalysts incorporated with large amounts of Al2O3 have higher selectivity for light hydrocarbons and lower selectivity for heavy hydrocarbons. 展开更多
关键词 Fischer-Tropsch synthesis iron-based catalyst Al2O3 binder Fe-Al2O3 interaction
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Effect of Manganese Incorporation Manner on an Iron-Based Catalyst for Fischer-Tropsch Synthesis 认领 引用 被引量：6
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作者 Tingzhen Li Yong Yang +5 位作者 Chenghua Zhang Zhichao Tao Haijun Wan Xia An Hongwei Xiang Yongwang Li 《Journal of Natural Gas Chemistry》 2007年第3期244-251,共8页
A systematic study was undertaken to investigate the effects of the manganese incorporation manner on the textural properties, bulk and surface phase compositions, reduction/carburization behaviors, and surface basici... A systematic study was undertaken to investigate the effects of the manganese incorporation manner on the textural properties, bulk and surface phase compositions, reduction/carburization behaviors, and surface basicity of an iron-based Fischer-Tropsch synthesis （FTS） catalyst. The catalyst samples were characterized by N2 physisorption, X-ray photoelectron spectroscopy （XPS）, H2 （or CO） temperature-programmed reduction （TPR）, CO2 temperature-programmed desorption （TPD）, and M5ssbauer spectroscopy. The FTS performance of the catalysts was studied in a slurry-phase continuously stirred tank reactor （CSTR）. The characterization results indicated that the manganese promoter incorporated by using the coprecipitation method could improve the dispersion of iron oxide, and decrease the size of the iron oxide crystallite. The manganese incorporated with the impregnation method is enriched on the catalyst＇s surface. The manganese promoter added with the impregnation method suppresses the reduction and carburization of the catalyst in H2, CO, and syngas because of the excessive enrichment of manganese on the catalyst surface. The catalyst added manganese using the coprecipitation method has the highest CO conversion （51.9%） and the lowest selectivity for heavy hydrocarbons （C12＋）. 展开更多
关键词 Fischer-Tropsch synthesis iron-based catalyst manganese promoter incorporation manner
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Effect of Addition Sequence during Neutralization and Precipitation on Iron-based Catalysts for High Temperature Shift Reaction 认领 引用 被引量：1
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作者 Li Wei Zhu Jianhua Mou Zhanjun 《Petroleum Science》 SCIE CAS 2007年第1期75-80,共6页
The preparation of the iron-based catalysts promoted by cobalt with a small amount of copper and aluminum for the high temperature shift reaction （HTS） with different sequences of adding catalyst raw materials durin... The preparation of the iron-based catalysts promoted by cobalt with a small amount of copper and aluminum for the high temperature shift reaction （HTS） with different sequences of adding catalyst raw materials during neutralization and precipitation was investigated. XRD, BET and particle size distribution （PSD） were used to characterize the prepared catalysts. It was found that the catalyst crystals were all γ-Fe2O3, and the intermediate of the catalyst after aging was Fe3O4. The crystallographic form of the catalyst and its intermediate was not affected by the addition sequence in the neutralization and precipitation process. The results showed that the specific surface area and the particle size of the catalysts depended on the addition sequence to the mother liquor. Cobalt with a small amount of copper and aluminum could increase the specific surface area and decrease the particle size of catalysts. 展开更多
关键词 Water gas shift reaction γ-Fe2O3 cobalt-promoted catalyst iron-based catalyst
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Review of Iron-Based Catalysts for Carbon Dioxide Fischer-Tropsch Synthesis 认领 引用 被引量：4
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作者 Ji-Yue Jia Yu-Ling Shan +3 位作者 Yong-Xiao Tuo Hao Yan Xiang Feng De Chen 《Transactions of Tianjin University》 EI CAS 2024年第2期178-197,共20页
Capturing and utilizing CO2from the production process is the key to solving the excessive CO2emission problem. CO2hydrogenation with green hydrogen to produce olefins is an effective and promising way to uti... Capturing and utilizing CO2from the production process is the key to solving the excessive CO2emission problem. CO2hydrogenation with green hydrogen to produce olefins is an effective and promising way to utilize CO2and produce valuable chemicals. The olefins can be produced by CO2hydrogenation through two routes, i.e., CO2-FTS (carbon dioxide Fischer- Tropsch synthesis) and MeOH (methanol-mediated), among which CO2-FTS has significant advantages over MeOH in practical applications due to its relatively high CO2conversion and low energy consumption potentials. However, the CO2-FTS faces challenges of difficult CO2activation and low olefins selectivity. Iron-based catalysts are promising for CO2-FTS due to their dual functionality of catalyzing RWGS and CO-FTS reactions. This review summarizes the recent progress on iron-based catalysts for CO2hydrogenation via the FTS route and analyzes the catalyst optimization from the perspectives of additives, active sites, and reaction mechanisms. Furthermore, we also outline principles and challenges for rational design of high-performance CO2-FTS catalysts. 展开更多
关键词 CO2hydrogenation Olefins CO2-FTS Iron-based catalysts
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Promoter effect on the CO_2-H_2O formation during Fischer-Tropsch synthesis on iron-based catalysts 认领 引用 被引量：1
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作者 Ali Nakhaei Pour Seyed Mehdi Kamali Shahri +1 位作者 Yahya Zamani Akbar Zamanian 《Journal of Natural Gas Chemistry》 2010年第2期193-197,共5页
The effects of Mg,La and Ca promoters on primary and secondary CO2 and H2O formation pathways during Fischer-Tropsch synthesis on precipitated Fe/Cu/SiO2 catalysts are investigated.The chemisorbed oxygen atoms in the ... The effects of Mg,La and Ca promoters on primary and secondary CO2 and H2O formation pathways during Fischer-Tropsch synthesis on precipitated Fe/Cu/SiO2 catalysts are investigated.The chemisorbed oxygen atoms in the primary pathway formed in the CO dissociation steps reacted with co-adsorbed hydrogen or carbon monoxide to produce H2O and CO2,respectively.The secondary pathway was the water-gas shift reaction.The results indicated that the CO2 production led to an increase in both primary and secondary pathways,and H2O production decreased when surface basicity of the catalyst increased in the order Ca 〉 Mg 〉 La. 展开更多
关键词 Ca promoter Mg promoter La promoter Fischer-Tropsch synthesis iron-based catalyst water-gas shift reaction
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Study of Manganese Promoter on a Precipitated Iron-Based Catalyst for Fischer-Tropsch Synthesis 认领 引用 被引量：11
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作者 Zhichao Tao Yong fang +4 位作者 Chenghua Zhang Tingzhen Li Mingyue Ding Hongwei Xiang Yongwang Li 《Journal of Natural Gas Chemistry》 2007年第3期278-285,共8页
The effects of Manganese （Mn） incorporation on a precipitated iron-based Fischer-Tropsch synthesis （FTS） catalyst were investigated using N2 physical adsorption, air differential thermal analysis （DTA）, H2 tempe... The effects of Manganese （Mn） incorporation on a precipitated iron-based Fischer-Tropsch synthesis （FTS） catalyst were investigated using N2 physical adsorption, air differential thermal analysis （DTA）, H2 temperature-programmed reduction （TPR）, and Mǒssbauer spectroscopy. The FTS performances of the catalysts were tested in a slurry phase reactor. The characterization results indicated that Mn increased the surface area of the catalyst, and improved the dispersion of （α-Fe2O3 and reduced its crystallite size as a result of the high dispersion effect of Mn and the Fe-Mn interaction. The Fe-Mn interaction also suppressed the reduction of （α-Fe2O3 to Fe3O4, stabilized the FeO phase, and （or） decreased the carburization degree of the catalysts in the H2 and syngas reduction processes. In addition, incorporated Mn decreased the initial catalyst activity, but improved the catalyst stability because Mn restrained the reoxidation of iron carbides to Fe3O4, and improved further carburization of the catalysts. Manganese suppressed the formation of CH4 and increased the selectivity to light olefins （C2-4^=）, but it had little effect on the selectivities to heavy （C5＋） hydrocarbons. All these results indicated that the strong Fe-Mn interaction suppressed the chemisorptive effect of the Mn as an electronic promoter, to some extent, in the precipitated iron-manganese catalyst system. 展开更多
关键词 Fischer-Tropsch synthesis iron-manganese catalyst manganese promoter Fe-Mn interaction
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Activation pressure studies with an iron-based catalyst for slurry Fischer-Tropsch synthesis 认领 引用 被引量：1
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作者 Qinglan Hao Liang Bai +1 位作者 Hongwei Xiang Yongwang Li 《Journal of Natural Gas Chemistry》 2009年第4期429-435,共7页
Fischer-Tropsch synthesis （FTS） was carried out with an industrial iron-based catalyst （100Fe/5Cu/6K/16SiO2, by weight） under the baseline conditions in a stirred tank slurry reactor （STSR）. The effects of activ... Fischer-Tropsch synthesis （FTS） was carried out with an industrial iron-based catalyst （100Fe/5Cu/6K/16SiO2, by weight） under the baseline conditions in a stirred tank slurry reactor （STSR）. The effects of activation pressure on the catalyst activity and selectivity were investigated. It was found that iron phase compositions, textural properties, and FTS performances of the catalysts were strongly dependent on activation pressure. The high activation pressure retards the carburization. MФssbauer effect spectroscopy （MES） results indicated that the contents of the iron carbides clearly decrease with the increase of activation pressure, especially for the activation pressure increasing from 1.0 MPa to 1.5 MPa, and the reverse trend is observed for superparamagnetic Fe^3＋ （spm）. The higher content of Fe^3＋ （spm） results in the higher amount of CO2 in tail gas when the catalyst is reduced at higher pressure. The catalyst activity decreases with the increase of activation pressure. The high quantity of iron carbides is necessary to obtain high FTS activity. However, the activity of the catalyst activated in syngas can not be predicted solely from the fraction of the carbides. It is concluded that activation with syngas at the lower pressure would be the most desirable for the better activity and stability on the iron-based catalyst. 展开更多
关键词 wFischer-Tropsch synthesis spray-dried iron catalyst activation pressure slurry reactor MCssbauer effect spectroscopy
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KINETICS OF IRON-BASED CATALYST IN TEMPERATURE-PROGRAMMED REDUCTION 认领 引用
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作者 梁斌 张鎏 《Chinese Journal of Chemical Engineering》 SCIE EI CAS 1996年第3期42-50,共9页
In this work, Temperature-Programmed Reduction Processes of iron oxide and 12 other kinds of promoted iron oxides were investigated. It is suggested that the reduction activation energy can be expressed as a normal di... In this work, Temperature-Programmed Reduction Processes of iron oxide and 12 other kinds of promoted iron oxides were investigated. It is suggested that the reduction activation energy can be expressed as a normal distribution. The distribution parameters were obtained by kinetic data fitting, which depends on the chemical and geometric characteristics of both the iron oxide and the promoter. 展开更多
关键词 temperature-programmed reduction iron-based catalyst reduction kinetics
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Study on Catalytic Behavior of Iron-based Catalyst with IITP as Electron Donor in the Polymerization of Butadiene 认领 引用 被引量：2
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作者 Shi-Liang Xu Ying-Nan Zhao +5 位作者 Yao Yu Qi Yang Li-Hua Na Heng Liu Chun-Yu Zhang Xue-Quan Zhang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第5期612-619,I0007,共8页
In this study,a novel iron-based catalyst system,Fe(acac)3/(isocyanoimino)triptenylphosphorane(IITP)/AlR3,was employed for the synthesis of syndiotactic 1,2-polybutadiene in hexane.This catalyst system exhibits remark... In this study,a novel iron-based catalyst system,Fe(acac)3/(isocyanoimino)triptenylphosphorane(IITP)/AlR3,was employed for the synthesis of syndiotactic 1,2-polybutadiene in hexane.This catalyst system exhibits remarkably high catalytic activity,achieving a polymerization activity of 762 kgpolymer·molcatalyst-1·h-1at 50℃with a[BD]/[Fe]molar ratio of 20000.Furthermore,living polymerization characteristic were observed during the investigation of the polymerization kinetics of 1,3-butadiene polymerization.These characteristics were well demonstrated by a narrow molecular weight distribution(PDI≈2.0)of the resulting polybutadiene and a linear relationship between-ln(1-c)and polymerization time as well as number average molecular weight and polymer yield.The resultant polymer showed a 1,2-selectivity of approximately 76%and stereoregularity ranging from 62%to 73%(rrrr).Additionally,through kinetic studies on polymerization reaction,an apparent activation energy Ea value of this catalytic system was calculated to be 84.98 kJ·mol-1,which suggests that high polymerization temperature favors efficient polymerization. 展开更多
关键词 Iron catalyst Syndiotactic 1,2-polybutadiene Elastomers Donor Selectivity
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Iron-based catalysts encapsulated by nitrogen-doped graphitic carbon for selective synthesis of liquid fuels through the Fischer-Tropsch process 认领 引用 被引量：4
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作者 Lei Tang Xiao‐Ling Dong +2 位作者 Wei Xu Lei He An‐Hui Lu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第12期1971-1979,共9页
Fischer‐Tropsch synthesis(FTS)has the potential to be a powerful strategy for producing liquid fuels from syngas if highly selective catalysts can be developed.Herein,a series of iron nanoparticle catalysts encapsula... Fischer‐Tropsch synthesis(FTS)has the potential to be a powerful strategy for producing liquid fuels from syngas if highly selective catalysts can be developed.Herein,a series of iron nanoparticle catalysts encapsulated by nitrogen‐doped graphitic carbon were prepared by a one‐step pyrolysis of a ferric L‐glutamic acid complex.The FeC‐800 catalyst pyrolyzed at 800°C showed excellent catalytic activity(239.4μmolCO gFe–1 s–1),high C5–C11 selectivity(49%),and good stability in FTS.The high dispersion of ferric species combined with a well‐encapsulated structure can effectively inhibit the migration of iron nanoparticles during the reaction process,which is beneficial for high activity and good stability.The nitrogen‐doped graphitic carbon shell can act as an electron donor to the iron particles,thus promoting CO activation and expediting the formation of Fe5C2,which is the key factor for obtaining high C5–C11 selectivity. 展开更多
关键词 Nitrogen doping Graphitic carbon Encapsulation Iron‐based catalyst Fischer‐Tropsch synthesis
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THE BEHAVIOR OF HOMOGENEOUS IRON-BASED CATALYSTS BEARING PYRIDINE DIIMINE LIGANDS FOR ETHYLENE POLYMERIZATION 认领 引用 被引量：2
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作者 李于飞 《Chinese Journal of Polymer Science》 SCIE EI CAS 2000年第6期509-513,共5页
The polymerization of ethylene by two iron-based catalysts, {[2,6-ArN=C(Me)(2)C5H3N]FeCl2} (Ar = 2,6-C6H3-Me-2 I; 2,6-C6H3 (i-Pr)(2) II) has been investigated. Catalyst II produces higher molecular weight polyethylene... The polymerization of ethylene by two iron-based catalysts, {[2,6-ArN=C(Me)(2)C5H3N]FeCl2} (Ar = 2,6-C6H3-Me-2 I; 2,6-C6H3 (i-Pr)(2) II) has been investigated. Catalyst II produces higher molecular weight polyethylene (PE) and broadened polydispersities relative to catalyst I under analogous conditions and all polymers are linear. The kinetic profiles with iron catalysts showed a smooth pattern during both rate build-up and rate lowering, which are different from the metallocene catalysts. The polymerization activity increases with Al/Fe value and an optimum temperature range at 40 similar to 45 degreesC was observed. The molecular weight of PE decreases with the increase of Al/Fe ratio and rise of polymerization temperature. 展开更多
关键词 ethylene polymerization transition metal catalyst
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Role of iron-based catalysts in reducing NOx emissions from coal combustion 认领 引用
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作者 Yuehua Liu Lili Chen +2 位作者 Shoujun Liu Song Yang Ju Shangguan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第7期1-8,共8页
Nitrogen oxide(NOx)pollutants emitted from coal combustion are attracting growing public concern.While the traditional technologies of reducing NOx were mainly focused on terminal treatment,and the research on s... Nitrogen oxide(NOx)pollutants emitted from coal combustion are attracting growing public concern.While the traditional technologies of reducing NOx were mainly focused on terminal treatment,and the research on source treatment is limited.This paper proposes a new coal combustion strategy that significantly reduces NOx emissions during coal combustion.This strategy has two important advantages in reducing NOx emissions.First,by introducing iron-based catalyst at the source,which will catalyze the conversion of coke nitrogen to volatile nitrogen during the pyrolysis process,thereby greatly reducing the coke nitrogen content.The second is de-NOx process by a redox reaction between NOx and reducing agents(coke,HCN,NH3,etc.)that occurred during coke combustion.Compared to direct combustion of coal,coke prepared by adding iron-based catalyst has 46.1% reduction in NOx emissions.To determine the effect of iron-based additives on de-NOx performance,demineralized coal(de-coal)was prepared to eliminate the effect of iron-based minerals in coal ash.The effects of iron compounds,additive dosages,and combustion temperatures on de-NOx efficiency are systematically studied.The results revealed that the NOx emission of the coke generated by pyrolysis of de-coal loaded with 3%(mass)Fe2O3 decreases to 27.3% at combustion temperature of 900℃.Two main reasons for lower NOx emissions were deduced:(1)During the catalytic coal pyrolysis stage,the nitrogen content in the coke decreases with the release of volatile nitrogen.(2)Part of the NOx emitted during the coke combustion was converted into N2 for the catalytic effect of the Fe-based catalysts.It is of great practical value and scientific significance to the comprehensive treatment and the clean utilization process of coal. 展开更多
关键词 NOx Coal combustion Coal pyrolysis Fe2O3 catalyst
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Construction of electron-rich active sites in the metallic active phase of iron-based hydrogenation catalysts and their regulation on HDN pathway selectivity 认领 引用
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作者 LI Xiaohan LI Meng +4 位作者 WEI Chongbin REN Shenyong GUO Qiaoxia ZHU Xiaochun SHEN Baojian 《燃料化学学报（中英文）》 EI CAS CSCD 北大核心 2026年第5期186-200,共15页
Hydrodenitrogenation(HDN)process is an effective method for removing nitrogen-containing heteroatom compounds from inferior feedstocks.Its core lies in developing catalysts with both low cost and high performance.In t... Hydrodenitrogenation(HDN)process is an effective method for removing nitrogen-containing heteroatom compounds from inferior feedstocks.Its core lies in developing catalysts with both low cost and high performance.In this study,a FeZn-supported catalyst was modified by introducing six different metal promoters(La,Ti,Ce,Mn,Mg and Cr).It was found that Cr exhibited a pronounced promotional effect on HDN performance.The promoting effect of Cr on the FeZn catalyst’s activity originates from its electronic interaction with sulfided Fe species,rather than functioning as an independent active site.Specifically,Cr and Zn species act synergistically as electron donors,transferring electron density to the sulfided Fe species.This thereby modulates the electronic structure of Fe,rendering it in an electron-rich state.The increased electronic density weakens the Fe-S bonds in the active phase,thereby promoting their cleavage.Consequently,it promotes the formation of hydrogenation active sites,known as coordinated unsaturated sulfur vacancies(CUS).After introducing 3%Cr,under conditions of 340-380℃,4 MPa pressure,and a high weight hourly space velocity(WHSV)of 8.7 h-1,the catalyst’s HDN conversion rate for the basic nitrogen compound quinoline increased by 14.5%-19.7%compared to the unmodified catalyst.The HDN conversion rate reached 81.9%at 380℃.Furthermore,the introduction of Cr increased the number of medium-strength Lewis acid sites.These acid sites work synergistically with the increased CUS sites,enhancing the overall hydrogenation activity of the catalyst.Cr addition effectively governs the selectivity of the HDN pathway.Consequently,the reaction rate constant for the deep hydrogenation pathway over the FeZn3Cr@GA catalyst reaches 3.2 times higher that of the unmodified FeZn@GA catalyst.In summary,using Fe as the primary active metal component and regulating its electronic structure through promoters represents an effective approach for designing low-cost,high-performance HDN catalysts. 展开更多
关键词 FeZnCr catalyst electron-rich Fe species quinoline hydrodenitrogenation C-N bond cleavage
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Syntheses and characterizations of oil-soluble iron-based catalysts for direct coal liquefaction 认领 引用
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作者 Dao Li Shansong Gao +4 位作者 Xu Li Chunlan Xiang Xiaojun Duan Jing Xie Xiangfeng Yu 《Clean Energy》 EI CSCD 2025年第5期136-148,共13页
Iron-based catalysts have been one of the most active fields in coal direct liquefaction technology due to their advantages of a vast source of raw materials,low synthesis cost,and high catalytic activities.In this st... Iron-based catalysts have been one of the most active fields in coal direct liquefaction technology due to their advantages of a vast source of raw materials,low synthesis cost,and high catalytic activities.In this study,five oil-soluble iron-based catalysts with different carbon chain lengths were synthesized by reacting a series of fatty acid sodium salts with trivalent iron salts as raw materials.The catalyst precursors synthesized were structurally characterized using inductively coupled plasma emission spectroscopy,Fourier transform infrared spectroscopy,and high-resolution mass spectrometry.In the presulfurization and activity evaluation experiments of coal direct liquefaction carried out in an autoclave,it was found by X-ray diffraction transmission electron microscopy and X-ray photoelectron spectrometry that the iron oleate catalysts formed highly catalytic Fe1−xS phases during the sulfurization process,with average particle sizes of∼200-300 nm and uniform distribution.The results of catalyst activity evaluation showed that under the same reaction conditions(temperature 455°C,reaction pressure 19 MPa,residence time 60 min)and,with the same addition amount of m(Fe)/m(dry coal)=1%,the iron oleate catalyst exhibited excellent catalytic performance,with a coal conversion of 89.45%and an extraction oil yield of 64.04%,which was significantly better than that of other oil-soluble iron-based catalysts.It is worth noting that the iron oleate catalyst can achieve comparable catalytic performance at a lower addition amount(m(Fe)/m(dry coal)=0.5 wt%)compared with the ultrafine hydrated iron oxide(FeOOH)catalyst,which requires an addition amount of m(Fe)/m(dry coal)=1 wt%.This not only reduces the cost of catalyst usage but also simplifies the subsequent dehydration and drying processes.The findings of this study hold significant importance for the development of new,high-efficiency catalysts for coal direct liquefaction and offer a theoretical foundation and technical support for the industrial application of coal-to-liquid technology. 展开更多
关键词 direct coal liquefaction oil-soluble iron-based catalysts iron oleate active phase liquefaction performance
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