Relationship between Iron Carbide Phases (ε-Fe2C, Fe7C3, and χ-Fe5C2) and Catalytic Performances of Fe/SiO2 Fischer–Tropsch Catalysts

Chang, Qiang; Zhang, Chenghua; Li, Chengwei; Wei, Yuxue; Cheruvathur, Ajin; Dugulan, A. Iulian; Niemantsverdriet, J.W.; Liu, Xingwu; He, Yurong; Qing, Ming; Zheng, Lirong; Yun, Yifeng; Yang, Yong; Li, Yongwang

doi:10.1021/acscatal.7b04085

Cited by 221 publications

(179 citation statements)

References 72 publications

Supporting

Mentioning

156

Contrasting

Order By: Relevance

“…S2 and figures S2 and S3), which has been reported as less active than the Fe5C2 and Fe7C3 phases in FTS [38,41]. Particularly, the Fe7C3 phase has the highest intrinsic activity among the carbides [51]. Another key difference is related to the Fe3O4 phase which has undergone a larger sintering with Fe/C+K catalyst, as derived from the higher intensities of the reflections belonging to the Fe3O4 phase within this sample, in agreement with the hypothesis that addition of K favors Fe reoxidation [52].…”

Section: Resultsmentioning

confidence: 96%

Metal Organic Framework-Derived Iron Catalysts for the Direct Hydrogenation of CO₂ to Short Chain Olefins

et al. 2018

View full text Add to dashboard Cite

We report the synthesis of a highly active, selective and stable catalyst for the hydrogenation of CO2 to short chain olefins in one single step by using a Metal Organic Framework as catalyst precursor. By studying the promotion of the resulting Fe(41 wt %)-carbon composites with different elements (Cu, Mo, Li, Na, K, Mg, Ca, Zn, Ni, Co, Mn, Fe, Pt and Rh) we have found that only K is able to enhance olefin selectivity. Further catalyst optimization in terms of promoter loading results in catalysts displaying unprecedented C2-C4 olefin space time yields: 33.6 mmol·gcat -1 ·h -1 at XCO2 = 40%, 320 ⁰ C, 30 bar, H2/CO2 = 3, and 24000 mL·g -1 ·h -1 . Extensive characterization demonstrates that K promotion affects catalytic performance by: (i) promoting a good balance between the different Fe active phases playing a role in CO2 hydrogenation, namely 2 iron oxide and iron carbides and by (ii) increasing CO2 and CO uptake while decreasing H2 affinity, interactions responsible for boosting olefin selectivity.

show abstract

Section: Resultsmentioning

confidence: 96%

Metal Organic Framework-Derived Iron Catalysts for the Direct Hydrogenation of CO₂ to Short Chain Olefins

et al. 2018

View full text Add to dashboard Cite

show abstract

“…The filtered cake was dried for 12 h at 120 °C and then calcined for 5 h at 500 °C in static air. The size of iron oxide in the fresh catalyst is about 5 nm …”

Section: Methodsmentioning

confidence: 99%

XAFS Studies of Fe−SiO₂ Fischer‐Tropsch Catalyst During Activation in CO, H₂, and Synthesis Gas

Chang

Zhang

et al. 2019

ChemCatChem

Self Cite

View full text Add to dashboard Cite

Highly dispersed catalysts are widely used in industry and academia because of their large surface active sites. However, the predominant short‐range ordered structures in catalysts cannot be revealed by bulk characterization tools. The present study chooses a highly dispersed Fe−SiO2 FTS catalyst as a research object and shows how X‐ray absorption fine structure (XAFS) helps to analyze the chemical information (iron composition, reduction degree, and iron valence) and structural information (coordinating atom and coordination number) of catalyst. The activation process of catalysts are detailedly studied under different atmospheres (CO, H2, or 2H2/CO) by using both ex‐situ and in‐situ XAFS. CO activation behaves most effective during the whole process and finally produces the highest content of active iron species compared with H2 and 2H2/CO activation. The coordination number evolution of nearest Fe−O and Fe−C shells around Fe are put forward to understand the activation process. The present study demonstrates how XAFS elaborately reveals the phase transformations of the highly dispersed Fe−SiO2 FTS catalyst.

show abstract

“…Hensen and co‐workers examined the FTS catalytic activity of pure‐phase Fe 2 C catalysts which exhibited stable FT performance at 235 °C and 23 bar for 150 h and showed extremely low selectivity toward CO 2 formation (see Figure b) . In addition, Fe 7 C 3 phase existed in a long‐term FTS process, and was demonstrated to be active for middle‐temperature (MT)‐FTS . Furthermore, iron carbides with different compositions (e.g., Fe 5 C 2 , Fe 2 C+Fe 5 C 2 , and Fe 7 C 3 +Fe 5 C 2 ) were obtained in the Fe/SiO 2 catalyst system by varying the pretreatment methods.…”

Section: Applications Of Fecx For Cox Hydrogenation and Electrochemicmentioning

confidence: 99%

Iron Carbides: Control Synthesis and Catalytic Applications in CO_x Hydrogenation and Electrochemical HER

Yang

Song

et al. 2019

Advanced Materials

View full text Add to dashboard Cite

Catalytic transformation of COx (x = 1, 2) with renewable H2 into valuable fuels and chemicals provides practical processes to mitigate the worldwide energy crisis. Fe‐based catalytic materials are widely used for those reactions due to their abundance and low cost. Novel iron carbides are particularly promising catalytic materials among the reported ferrous catalysts. Recently, a series of strategies has been developed for the preparation of iron carbide nanoparticles and their nanocomposites. Control synthesis of FeCx‐based nanomaterials and their catalytic applications in COx hydrogenation and electrochemical hydrogen evolution reaction (HER) are reviewed. The discussion is focused on the unique catalytic activities of iron carbides in COx hydrogenation and HER and the correlation between structure and catalytic performance. Future synthesis and potential catalytic applications of iron carbides are also summarized.

show abstract

Relationship between Iron Carbide Phases (ε-Fe₂C, Fe₇C₃, and χ-Fe₅C₂) and Catalytic Performances of Fe/SiO₂ Fischer–Tropsch Catalysts

Cited by 221 publications

References 72 publications

Metal Organic Framework-Derived Iron Catalysts for the Direct Hydrogenation of CO₂ to Short Chain Olefins

Metal Organic Framework-Derived Iron Catalysts for the Direct Hydrogenation of CO₂ to Short Chain Olefins

XAFS Studies of Fe−SiO₂ Fischer‐Tropsch Catalyst During Activation in CO, H₂, and Synthesis Gas

Iron Carbides: Control Synthesis and Catalytic Applications in CO_x Hydrogenation and Electrochemical HER

Contact Info

Product

Resources

About

Relationship between Iron Carbide Phases (ε-Fe2C, Fe7C3, and χ-Fe5C2) and Catalytic Performances of Fe/SiO2 Fischer–Tropsch Catalysts

Cited by 221 publications

References 72 publications

Metal Organic Framework-Derived Iron Catalysts for the Direct Hydrogenation of CO2 to Short Chain Olefins

Metal Organic Framework-Derived Iron Catalysts for the Direct Hydrogenation of CO2 to Short Chain Olefins

XAFS Studies of Fe−SiO2 Fischer‐Tropsch Catalyst During Activation in CO, H2, and Synthesis Gas

Iron Carbides: Control Synthesis and Catalytic Applications in COx Hydrogenation and Electrochemical HER

Contact Info

Product

Resources

About

Relationship between Iron Carbide Phases (ε-Fe₂C, Fe₇C₃, and χ-Fe₅C₂) and Catalytic Performances of Fe/SiO₂ Fischer–Tropsch Catalysts

Metal Organic Framework-Derived Iron Catalysts for the Direct Hydrogenation of CO₂ to Short Chain Olefins

Metal Organic Framework-Derived Iron Catalysts for the Direct Hydrogenation of CO₂ to Short Chain Olefins

XAFS Studies of Fe−SiO₂ Fischer‐Tropsch Catalyst During Activation in CO, H₂, and Synthesis Gas

Iron Carbides: Control Synthesis and Catalytic Applications in CO_x Hydrogenation and Electrochemical HER