CATALYSIS TODAY
·
2020
·
IF 5.825
Junhui Liu,Guanghui Zhang,Xiao Jiang,Junhu Wang,Chunshan Song,Xinwen Guo
Iron-based catalysts have been widely used to synthesize value-added hydrocarbons through CO 2 hydrogenation. Fe carbide, Fe 5 C 2 , was proposed as the active phase responsible for C C coupling during the chain growth. However, the reaction mechanism over iron-based catalysts is still under debate due to the presence of multiple phases of Fe species. In this work, Fe 5 C 2 and K-modified Fe 5 C 2 were prepared and used to study the relationship between the Fe phase, catalytic performance and reaction pathways. CH 4 and CO selectivities of 46.1 C-mol% and 2.8 C-mol% were obtained on Fe 5 C 2 at a CO 2 conversion of 49.8 %, with the main hydrocarbon products being alkanes. With the addition of the promoter K, the C 2 -C 4 = selectivity increased to above 38.0 C-mol%, and the selectivity to C 5+ hydrocarbons increased to 23.9 C-mol% at a similar CO 2 conversion. CH 4 and C 2+ hydrocarbons formed through the CO 2 →CO→hydrocarbons (indirect) route over K-modified Fe 5 C 2 , whereas the direct hydrogenation route occurred on unmodified Fe 5 C 2 in addition to the indirect route of CO 2 to CO to hydrocarbons through Fischer-Tropsch synthesis (FTS) processes. This work offers insights in direct CO 2 hydrogenation over Fe 5 C 2 and Fe 3 O 4 -Fe 5 C 2 catalysts, which advances the understanding of the functions of active phases and reaction pathways of CO 2 hydrogenation over iron-based catalysts.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Yanqiu Wang,Ying Zhou,Xinxin Zhang,Mingrui Wang,Tangkang Liu,Jinxing Wei,Guanghui Zhang,Xinlin Hong,Guoliang Liu
Direct CO 2 hydrogenation to higher alcohols (HA) is a promising route for high-value utilization of waste CO 2 , but developing active and stable catalysts remains a grand challenge. For this reaction, constructing multifunctional interfaces as active sites is required to fulfill controllable C-C coupling of alkyl and CO*/CH x O* species. Herein, we report a PdFe catalyst with abundant PdFe alloy-Fe 5 C 2 interfaces via a PdFe alloy induced FeO x carbidization process, which can achieve HA yield of 86.5 mg g cat −1 h −1 with 26.5% selectivity at 300 ºC, 5 MPa, and 6000 mL g cat −1 h −1 . The accelerated deactivation test unveils the PdFe catalyst exhibits better durability than the widely studied CuFe based catalysts against harsh conditions. Multiple in-situ characterization results unveil a synergetic mechanism for HA synthesis at the PdFe alloy-Fe 5 C 2 interfaces, where PdFe alloy is responsible for CO formation and non-dissociative activation, while Fe 5 C 2 phase promotes CO dissociation and chain propagation.
研究领域:
化学工程
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催化科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Daoping Ye,Wenxiang Tang,Tao Zhang,Li Lv,Zongpeng Zou,Raju Kumar Gupta,Shengwei Tang
CO 2 hydrogenation to olefines is a feasible carbon capture and utilization (CCU) route. The process includes sequential reactions of reverse water gas shift (RWGS) reaction and Fischer-Tropsch synthesis (FTS) reaction. The acceleration of FTS is crucial to improve the olefines yield. A microemulsion anti-solvent extraction (MAE) method was proposed to prepare Fe-based catalyst on the support of Al 2 O 3 . Ethanol solution of Fe(NO 3 ) 3 was encapsulated in microdroplets, and then loaded on Al 2 O 3 by the extraction of ethanol from the microdroplets to isooctane phase. The average size of micro droplets was 7.5 nm. After calcination , the particle size of Fe 2 O 3 was 6 nm. After carburization with CO, the interface formed between Fe 3 O 4 and Fe 5 C 2 was restricted in a narrow space with a mean size of 12 nm. Through TEM-Mapping, XRD , XPS and TPC characterization, the distribution uniformity of Fe and the neighboring degree of Fe 3 O 4 and Fe 5 C 2 on the as-prepared catalyst MAE-Fe 1 K 1 was improved effectively. An enhanced synergistic effect between Fe 3 O 4 and Fe 5 C 2 was obtained. The catalytic performance evaluation results showed that yield of C 2 -C 4 olefins reached 0.063 mmol·gFe −1 ·s −1 after 12 h of reaction. It exhibited better catalytic performance than most catalysts reported in the literatures. The results showed that the proposed microemulsion anti-solvent extraction strategy is an effective method to prepare Fe-based catalyst for CO 2 -FTO reaction with an excellent catalytic performance.
研究领域:
催化化学
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材料科学
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环境科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Mingshuai Sun,Fumin Wang,Guojun Lv,Xubin Zhang
Overhydrogenation to ethane is most undesired in selective hydrogenation of acetylene. Monometallic Pd supported on common oxide supports such as alumina and silica suffers from susceptibility of ethane formation, and the ethylene selectivity is usually unsatisfactory. Herein, Fe5C2 was carefully synthesized and employed as a new kind support doped with a (5–600) ppm level of Pd for selective hydrogenation of acetylene. The catalyst with appropriate Pd loadings exhibited more efficient ethane suppression and much higher ethylene selectivity than the traditional α-Al2O3 supported Pd catalyst, with full acetylene conversion under 240 °C, and maintained good stability after a 200 h tolerance test. Characterization and DFT calculation results reveal that the excellent ethylene selectivity is mainly derived from the special interaction between Pd atoms and the Fe5C2 support. Hydrogenation of ethylene to ethane needs to cross extremely high activation energy barriers on the catalyst surface, and ethylene desorption more easily occurs on it. Doping the appropriate amount of Pd atoms on the Fe5C2 surface can increase the obstacle for polymerization and will cause the unsaturated C2 species to be more inclined to be hydrogenated into C2H4. This synergy effect also acts as a guide in alkane suppression for selective hydrogenation of other alkynes.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Sijun Yang,Jie Yu,Chengli Yao,Shikuo Li,Anjian Xie
The development of efficient non-precious-metal catalysts for oxygen reduction reaction (ORR) is greatly important for accelerating the commercial application of fuel cells. Herein, polystyrene (PS) nanospheres are used as templates for the growth of zeolitic imidazolate framework (ZIF) complex precursors with variable molar ratios of Fe 3+ to Zn 2+ in situ. Through carbonization at a high temperature, the hierarchical porous carbon (HPC) materials with different proportions (xFeyZn-HPC, x + y = 100) have been prepared. The typical product 5Fe95Zn-HPC is composed of nitrogen (N)-doped hierarchical porous carbon loaded with Fe/Fe 5 C 2 nanoparticles obtained at optimal molar ratio. As an electrocatalyst, the 5Fe95Zn-HPC shows a positive onset potential of 0.92 V (vs. RHE), half-wave potential of 0.77 V (vs. RHE) and limiting current density of 5.60 mA cm −2 at 0.055 V (vs. RHE). The hydrogen peroxide yield is less than 4.2%, and the electron transfer numbers are between 3.91 and 3.99 at 0.055 V~1.055 V in the catalytic ORR, which indicate that the reaction is dominated by four-electron reduction. The 5Fe95Zn-HPC has higher stability and methyl alcohol resistance in alkaline and acidic solutions. The above results indicate the excellent catalytic ORR performance of the 5Fe95Zn-HPC, almost as the commercial Pt/C. Additionally, 5Fe95Zn-HPC has the capacity to catalyze oxygen evolution reaction (OER) and adsorb methylene blue pollutants. Therefore, this work provides a practical method to design the hierarchical porous carbon-based material with outstanding multi-functions.
研究领域:
材料科学
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电化学
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能源科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Weifeng Tu,Chao Sun,Zhengzhou Zhang,Wenqi Liu,Haripal Singh Malhi,Wei Ma,Minghui Zhu,Yi-Fan Han
This work unravels the chemical and structural properties of Fe 5 C 2 -ZnO catalysts decorated with sodium (Na) during CO 2 hydrogenation to linear α-olefins, determined by rate assessments and series of in-situ characterizations. Reaction network remains as a combination of reverse water-gas-shift (RWGS) and CO hydrogenation, but their relative contributions vary. The RWGS reaction is chemically equilibrated, thus CO 2 conversion is determined solely by the thermodynamic constraint. However, Na addition alleviates the formation rates of paraffins from the subsequent CO hydrogenation and reactions of olefins with hydrogen. Na additive does not alter the structures of Fe 5 C 2 -ZnO, but improves largely the stability of Fe 5 C 2 by preventing the phase oxidation during the reaction. Na modifies the surface properties of catalyst, thus facilitates reaction of CO* and H* and the C C bond formation. The dual role of Na leads more effective olefins turnovers and provides new insights to the design of novel catalysts for CO 2 utilization.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Junhui Liu,Anfeng Zhang,Xiao Jiang,Min Liu,Jie Zhu,Chunshan Song,Xinwen Guo
Conversion of CO2 by hydrogenation into higher hydrocarbons has attracted much attention due to the continuous increasing concentration of CO2 in the atmosphere. Fe5C2 was used as the active site and mixed with K-modified supports for CO2 hydrogenation to synthesize value-added hydrocarbons. A series of supports were tested, and the alkaline Al2O3 was the best choice for light olefins and C5+ hydrocarbons. The transformation of product selectivity at time on stream demonstrated that potassium migrated into Fe5C2 during reaction. The selectivity of C2+ is 69.2% containing 35.8% C2–C4= and 29.1% C5+ value-added hydrocarbons with the 31.5% CO2 conversion (H2/CO2 = 3). When the ratio of H2 and CO2 was switched to 4, CO2 conversion improved to 40.9%, and the C2+ selectivity to 73.5%, containing 37.3% C2–C4= and 31.1% C5+ value-added hydrocarbons. The mixture catalysts can be directly used without any reduction before reaction, reducing the consumption H2 and simplifying the operation.
研究领域:
催化化学
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能源化学
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环境科学
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材料化学
·
工业催化
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Zixiang Song,Mingmei Zhang,Zhuokai Wang,Zhiye Huang,An Wang,Guisheng Zhu,Shouyan Shao
Herein, a new metal organic framework MOF derived CoFe-Fe 5 C 2 nanoparticles embedded nitrogen doped graphitized carbon/ nitrogen doped carbon nanotubes (CoFe-Fe 5 C 2 @NC/CNTs) heterostructures is successfully achieved through calcination in dicyandiamide atmosphere using Co/Fe-MOF as a precursor. The morphologies display that CoFe and Fe 5 C 2 are uniformly dispersed in the framework of nitrogen doped carbon and dicyandiamide forms NCNTS using cobalt as a graphitization catalyst. The as prepared CoFe-Fe 5 C 2 @NC/CNTs hybrids exhibit remarkable specific properties of 60.23 mA cm −2 and small Tafel slope of 106.2 mV dec −1 in potential window from 0.4 V to 0.9 V towards methanol electro- oxidation reaction (MOR) in alkaline solution. At the same time, it realize more excellent stability comparing to that of CoFe-Fe 5 C 2 @NC electrocatalyst, which attributed to the interconnected ion/electron channels of abundant interfaces anchored nitrogen doped carbon nanotubes and the thin layer nitrogen doped graphitized carbon anchor the ultra-fine Fe 5 C 2 and CoFe particles accelerating the charge transport. More importantly, CoFe-Fe 5 C 2 @NC presents 94.6% retention of initial MOR activity during CO poisoning test. This strategy will provide new ideas for the control of the composite structure of transition metal carbides using MOF derivatives, and provide technical support for the development of efficient and CO-resistant non noble metal electrocatalysts.
研究领域:
材料科学
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电催化
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能源化学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 12
·期 3
·762-772
·
IF 6.119
Yitao Liu,Xianglin Liu,Zixu Yang,Hu Li,Xiaoxu Ding,Minjie Xu,Xinli Li,Wei-Feng Tu,Minghui Zhu,Yi-Fan Han
We reported a χ-Fe5C2/MgO catalyst for olefin synthesis directly from syngas (STO), showing high selectivity to C2–C4 olefins and catalytic stability. With characterization of the morphology, electronic structures, and adsorption/desorption properties using in/ex situ techniques (XPS, TEM, XRD, MES, PHTA and TPD), we revealed that MgO could act not only as a structural promoter to disperse the active iron phase and prevent particle agglomeration during the reaction, but also as an electronic modifier to transfer electrons to iron. In particular, by combination of spectroscopy and theory calculations, we have proved that the close intimacy between χ-Fe5C2 and MgO (∼0.3 electrons transfer from MgO to χ-Fe5C2) enhanced CO dissociative adsorption whilst weakening the secondary hydrogenation of olefins, leading to the enhancement of selectivity. The dual roles of MgO in χ-Fe5C2/MgO may shed light upon rational design of practical STO catalysts by taking advantage of the exceptional strong metal–support interactions (SMSIs).
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2022
·
IF 11.307
Bo Jiang,Wang Yang,Hengxuan Bai,Chaonan Wang,Chong Xu,Zhengxuan Li,Lu Yan,Chengxiao Zhang,Ni Wu,Sai Che,Xiaobai Wang,Yongfeng Li
The challenge of realizing low filler loading and high-performance microwave absorbing (MA) materials is still an urgent issue to be solved. Herein, porous N-doped carbon wrapped Fe/Fe 5 C 2 (Fe/Fe 5 C 2 @NC) nanocomposite is successfully synthesized by a facile one-step calcination of carbon nitride and ferrocene precursors. The magnetic Fe/Fe 5 C 2 nanoparticles are tightly and uniformly anchored on the wrinkled carbon nanosheets . Abundant of voids exist between the three-dimensional conductive carbon network, which can result in a low density and a strong interfacial polarization relaxation with effect. Based on the double attenuation mechanisms of dielectric loss and magnetic loss, the optimized Fe/Fe 5 C 2 @NC-800 possesses a minimum reflection loss value reaching −63.1 dB and an effective absorption bandwidth (EAB) as broad as 7.3 GHz with an extremely low filler loading of 4 wt%. The Fe/Fe 5 C 2 @NC-800 can even achieve a broad EAB within 4.5–18.0 GHz by tuning the absorber thickness in the range of 2.5–5.0 mm, covering nearly 85% of the whole measured frequency band. This work provides new insights for the development of advanced lightweight MA materials, which has wide effective absorption frequency range and strong absorption intensity at low filling levels.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 83
·79459-79469
·
IF 3.289
Yue Guan,Zhiyu Dou,Yan Yang,Juanhong Xue,Zhen Zhu,Lili Cui
We have synthesized hierarchically 3D porous Fe5C2/N-doped graphene (3D Fe5C2/N-PG) with numerous micro/meso-pores by a controllable and facile strategy. The density of the micro/meso-pores can be accurately tailored by adjusting the reaction conditions. It is found that the ORR performance of the electrocatalyst is strongly dependent on the pore structures under the same conditions. The electrocatalyst exhibits comparable activity in an acidic solution together with superior activity in an alkaline solution to the state-of-the-art Pt/C catalyst in terms of onset potential, half-wave potential, diffusion-limiting current density and kinetic current density. The excellent electrocatalytic activity is attributed to the balance of the surface area, hierarchical porosity, chemical composition (pyridinic N, graphitic N and Fe5C2 nanoparticles) and conductivity of the 3D interconnected graphene. This strategy for the tunable synthesis of hierarchically 3D porous graphene materials offers a platform for developing catalysts with superior activity in energy devices.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Haripal Singh Malhi,Zhenzhou Zhang,Yanling Shi,Xinhua Gao,Wenqi Liu,Weifeng Tu,Yi-Fan Han
The multi-walled carbon nanotubes (MWNTs) supported Fe-based catalysts, including FeZnNa/MWNTs, FeZnK/MWNTs, and FeZnRb/MWNTs were synthesized through co-precipitation, and incipient wetness impregnation approaches. The physicochemical results demonstrated that the addition of MWNTs had significantly influenced the morphology, reduction, phase structure, adsorption behavior of Fe-based catalysts, and consequently, the reactivity of CO 2 hydrogenation to olefins. Furthermore, adding MWNTs to the alkali metal-promoted FeZn catalysts inhibits the synthesis of CH 4 and CO and favors an improved selectivity for olefins. With the incorporation of MWNTs, the heavy olefins (C 5- C 8 = ) selectivity over FeZnNa, FeZnK, and FeZnRb catalysts increased from 27.1 to 32.2, 27.0–31.1, and 24.2–28.6 %, respectively. The results proved that the superior selectivity of heavy olefin over the MWNTs-supported catalysts might be accomplished by the electron-donating ability of the MWNTs surface, the presence of extra Hägg carbide, and higher adsorption strength with light olefins. In addition, the catalyst supported by MWNTs demonstrated exceptional stability throughout the 100-hour test at 593 K.
研究领域:
化学工程
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）