Synthesis of stable and low-CO
            <sub>2</sub>
            selective ε-iron carbide Fischer-Tropsch catalysts

Wang, Peng; Chen, Wei; Chiang, Fu-Kuo; Dugulan, A. Iulian; Song, Yuanjun; Pestman, Robert; Zhang, Kui; Yao, Jinsong; Feng, Bo; Miao, Ping; Xu, Wayne Qiang; Hensen, Emiel J. M.

doi:10.1126/sciadv.aau2947

“…There is general agreement that under reaction conditions these various phases co‐exist and their relative concentrations undergo dynamic changes . Among them, iron carbides are thought to be crucial for the formation of hydrocarbons, while iron oxides have been identified as being active for WGS/RWGS reactions . Thus, since the pretreatment of the Fe 2 O 3 /Al 2 O 3 catalyst was performed at 300 °C, and at this temperature the catalyst is comprised mostly FeO phase, then this is an indication that the FeO phase is responsible for the observed RWGS reactivity of this catalyst.…”

Section: Resultsmentioning

confidence: 92%

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO₂ Hydrogenation to Hydrocarbons

Aitbekova

¹

,

Goodman

²

,

Wu

³

et al. 2019

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Catalytic CO2 reduction to fuels and chemicals is a major pursuit in reducing greenhouse gas emissions. One approach utilizes the reverse water‐gas shift reaction, followed by Fischer–Tropsch synthesis, and iron is a well‐known candidate for this process. Some attempts have been made to modify and improve its reactivity, but resulted in limited success. Now, using ruthenium–iron oxide colloidal heterodimers, close contact between the two phases promotes the reduction of iron oxide via a proximal hydrogen spillover effect, leading to the formation of ruthenium–iron core–shell structures active for the reaction at significantly lower temperatures than in bare iron catalysts. Furthermore, by engineering the iron oxide shell thickness, a fourfold increase in hydrocarbon yield is achieved compared to the heterodimers. This work shows how rational design of colloidal heterostructures can result in materials with significantly improved catalytic performance in CO2 conversion processes.

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“…[14] There is general agreement that under reaction conditions these various phases co-exist and their relative concentrations undergo dynamic changes. [14] Among them, iron carbides are thought to be crucial for the formation of hydrocarbons, [15] while iron oxides have been identified as being active for WGS/RWGS reactions. [3a] Thus, since the pretreatment of the Fe 2 O 3 /Al 2 O 3 catalyst was performed at 300 8 8C, and at this temperature the catalyst is comprised mostly FeOp hase,t hen this is an indication that the FeOp hase is responsible for the observed RWGS reactivity of this catalyst.…”

Section: Resultsmentioning

confidence: 99%

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO₂ Hydrogenation to Hydrocarbons

Aitbekova

¹

,

Goodman

²

,

Wu

³

et al. 2019

View full text Add to dashboard Cite

Catalytic CO2 reduction to fuels and chemicals is a major pursuit in reducing greenhouse gas emissions. One approach utilizes the reverse water‐gas shift reaction, followed by Fischer–Tropsch synthesis, and iron is a well‐known candidate for this process. Some attempts have been made to modify and improve its reactivity, but resulted in limited success. Now, using ruthenium–iron oxide colloidal heterodimers, close contact between the two phases promotes the reduction of iron oxide via a proximal hydrogen spillover effect, leading to the formation of ruthenium–iron core–shell structures active for the reaction at significantly lower temperatures than in bare iron catalysts. Furthermore, by engineering the iron oxide shell thickness, a fourfold increase in hydrocarbon yield is achieved compared to the heterodimers. This work shows how rational design of colloidal heterostructures can result in materials with significantly improved catalytic performance in CO2 conversion processes.

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“…It was found that Fe 3 C and Fe 5 C 2 were the dominant phases at 625 and 700 °C, respectively. Hensen and co‐workers synthesized pure‐phase Fe 2 C by carefully controlling the pretreatment and carburization processes (see Figure a) . It was concluded that the precursor must be completely reduced to metallic Fe, otherwise the products could become a mixture of iron carbides and oxides, because Fe 3 O 4 could not be carburized under the synthesis gas (H 2 /CO/N 2 ) at 250 °C.…”

Section: Control Synthesis Of Iron Carbidesmentioning

confidence: 99%

Section: Control Synthesis Of Iron Carbidesmentioning

confidence: 99%

“…Fe 2 C is considered as an active phase at low temperature and/or low H 2 /CO ratios FTS process . 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 .…”

Section: Applications Of Fecx For Cox Hydrogenation and Electrochemicmentioning

confidence: 99%

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

Li

¹

,

Yang

²

,

Song

³

et al. 2019

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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.

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Synthesis of stable and low-CO ₂ selective ε-iron carbide Fischer-Tropsch catalysts

Abstract: Phase-pure ε-iron carbide catalysts amenable to scale-up exhibit low CO2 selectivity and high stability in the FT reaction.

Cited by 152 publications

References 33 publications

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO₂ Hydrogenation to Hydrocarbons

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO₂ Hydrogenation to Hydrocarbons

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO₂ Hydrogenation to Hydrocarbons

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

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Synthesis of stable and low-CO 2 selective ε-iron carbide Fischer-Tropsch catalysts

Abstract: Phase-pure ε-iron carbide catalysts amenable to scale-up exhibit low CO2 selectivity and high stability in the FT reaction.

Cited by 152 publications

References 33 publications

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO2 Hydrogenation to Hydrocarbons

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO2 Hydrogenation to Hydrocarbons

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO2 Hydrogenation to Hydrocarbons

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

Contact Info

Product

Resources

About

Synthesis of stable and low-CO ₂ selective ε-iron carbide Fischer-Tropsch catalysts

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO₂ Hydrogenation to Hydrocarbons

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO₂ Hydrogenation to Hydrocarbons

Engineering of Ruthenium–Iron Oxide Colloidal Heterostructures: Improved Yields in CO₂ Hydrogenation to Hydrocarbons

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