Pyrolysis of Metal–Organic Frameworks to Fe3O4@Fe5C2 Core–Shell Nanoparticles for Fischer–Tropsch Synthesis

Iron-based nanoparticles embedded in a graphitic layer of carbon architectures as stable heterogeneous Friedel–Crafts acylation catalysts

Carbon supported iron nanoparticles were prepared by pyrolyzing Fe-MOF material of Fe-diamine-dicarboxylic acid, and showed excellent catalytic activity and stability for the Friedel–Crafts acylation of aromatic compounds with acyl chloride.

Structural evolution of carbon in an Fe@C catalyst during the Fischer–Tropsch synthesis reaction

A pseudo-in situ research method was applied to provide insight into the structural evolution of carbon in an Fe@C catalyst at different stages of the Fischer–Tropsch reaction.

Effect of a potassium promoter on the Fischer–Tropsch synthesis of light olefins over iron carbide catalysts encapsulated in graphene-like carbon

Enhanced FTO catalyst performance and catalyst stability are achieved over a graphene-like carbon encapsulated iron carbide catalyst, which is prepared by a facile pyrolysis method.

Metal-Organic Frameworks as Platforms for Catalytic Applications

Metal-organic frameworks (MOFs), also called porous coordination polymers, represent a class of crystalline porous materials built from organic linkers and metal ions/clusters. The unique features of MOFs, including structural diversity and tailorability as well as high surface area, etc., enable them to be a highly versatile platform for potential applications in many fields. Herein, an overview of recent developments achieved in MOF catalysis, including heterogeneous catalysis, photocatalysis, and eletrocatalysis over MOFs and MOF-based materials, is provided. The active sites involved in the catalysts are particularly emphasized. The challenges, future trends, and prospects associated with MOFs and their related materials for catalysis are also discussed.

Influence of precursor porosity on sodium and sulfur promoted iron/carbon Fischer-Tropsch catalysts derived from metal-organic frameworks

Iron-based metal-organic frameworks (MOFs) with varying porosity are converted by pyrolysis into iron/carbon catalysts with predetermined composition and tailored pore structural features for the Fischer-Tropsch synthesis of lower C₂-C₄ olefins. Significantly higher activity arises for catalysts with higher porosity and decreased iron particle size derived from hierarchical MOF xerogel/aerogel precursors as compared to a purely microporous MOF. Post-synthetic functionalization using sodium and sulfur promoters further enhances the catalytic properties.

Fe2O3 hollow microspheres as highly selective catalysts for the production of α-olefins

Fe₂O₃ derived from Fe-glycerate with different interior structures and tunable pore sizes distinctly optimized the product selectivity.

Supported Fe/MnOx catalyst with Ag doping for remarkably enhanced catalytic activity in Fischer–Tropsch synthesis

The role of Ag in the promotion of the FTS performance and the evolutions of structure and phase over the Fe/MnO_x catalyst has been clearly elucidated.

Carbon-encapsulated highly dispersed FeMn nanoparticles for Fischer–Tropsch synthesis to light olefins

The peculiar structure of FeMn@C not only facilitates the formation of χ-Fe₅C₂, but it also promotes the product selectivity of light olefins.

One-pot synthesis of carbon-coated Fe3O4 nanoparticles with tunable size for production of gasoline fuels

Fe₃O₄@C nanoparticles with tunable size exhibit excellent catalytic performance in the direct synthesis of gasoline fuels.

Enhancing the light olefin selectivity of an iron-based Fischer–Tropsch synthesis catalyst by modification with CTAB

The effects of the surfactant hexadecyltrimethylammonium bromide (CTAB) on the catalytic performance of a manganese-promoted iron (FeMn) catalyst for the Fischer–Tropsch to olefin (FTO) reaction were investigated. The use of the CTAB-assisted FeMn catalyst resulted in the production of light olefin (C_2–4 ^{Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]>} ) selectivity of up to 55.45% with a ratio of olefin to paraffin among the C₂–C₄ hydrocarbons as high as 7.75 under industrially relevant conditions (320 °C, 1.0 MPa, H₂/CO ratio of 1.5 (v/v), GHSV = 4200 h⁻¹). The characterization results indicate that CTAB has a great influence on the structure, composition, chemical state, and catalytic performance of the iron-based catalyst. Most interestingly, a greater amount of Mn promoter was found to be dispersed on the surface of α-Fe₂O₃, rather than being dissolved into the α-Fe₂O₃ lattice when CTAB was employed, which contributed towards enhancing the promotional effects of the Mn promoter, leading to the formation of certain surface-specific activity sites.

The effects of the surfactant hexadecyltrimethylammonium bromide (CTAB) on the catalytic performance of a manganese-promoted iron (FeMn) catalyst for the Fischer–Tropsch to olefin (FTO) reaction were investigated.

A simple high-yield synthesis of high-purity Hägg carbide (χ-Fe5C2) nanoparticles with extraordinary electrochemical properties

Iron carbides are of eminent interest in both fundamental scientific research and in the industry owing to their properties such as excellent mechanical strength and chemical inertness. They have been found very effective in Fischer-Tropsch synthesis exploring heterogeneous catalysis for the production of chemicals such as liquid fuel and they have also been employed as successful promoters for the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). However, so far there have been only a few reports on the application of iron carbide nanoparticles in the field of electrochemical sensing. Here, we present a stable form of Hägg carbide nanoparticles synthesized from a rare form of iron(iii) oxide (β-Fe₂O₃). The as-prepared nanomaterial was characterized employing X-ray powder diffraction and Mössbauer spectroscopy to prove its composition as well as an extraordinary high purity level. It turned out that Hägg carbide nanoparticles prepared by thermally treated β-Fe₂O₃ exhibited excellent electrochemical properties including low charge transfer resistivity (R_ct) compared to the other tested materials. Moreover, the Hägg carbide nanoparticles were tested as a promising electrocatalyst for voltammetric detection of the antibiotic metronidazole proving its practical applicability.

Structural and elemental influence from various MOFs on the performance of Fe@C catalysts for Fischer–Tropsch synthesis

The structure and elementary composition of various commercial Fe-based MOFs used as precursors for Fischer–Tropsch synthesis (FTS) catalysts have a large influence on the high-temperature FTS activity and selectivity of the resulting Fe on carbon composites. The selected Fe-MOF topologies (MIL-68, MIL-88A, MIL-100, MIL-101, MIL-127, and Fe-BTC) differ from each other in terms of porosity, surface area, Fe and heteroatom content, crystal density and thermal stability. They are re-engineered towards FTS catalysts by means of simple pyrolysis at 500 °C under a N₂ atmosphere and afterwards characterized in terms of porosity, crystallite phase, bulk and surface Fe content, Fe nanoparticle size and oxidation state. We discovered that the Fe loading (36–46 wt%) and nanoparticle size (3.6–6.8 nm) of the obtained catalysts are directly related to the elementary composition and porosity of the initial MOFs. Furthermore, the carbonization leads to similar surface areas for the C matrix (S_BET between 570 and 670 m² g⁻¹), whereas the pore width distribution is completely different for the various MOFs. The high catalytic performance (FTY in the range of 1.9–4.6 × 10⁻⁴ mol_CO g_Fe⁻¹ s⁻¹) of the resulting materials could be correlated to the Fe particle size and corresponding surface area, and only minor deactivation was found for the N-containing catalysts. Elemental analysis of the catalysts containing deliberately added promoters and inherent impurities from the commercial MOFs revealed the subtle interplay between Fe particle size and complex catalyst composition in order to obtain high activity and stability next to a low CH₄ selectivity.

Fe/Fe3C@N-doped porous carbon hybrids derived from nano-scale MOFs: robust and enhanced heterogeneous catalyst for peroxymonosulfate activation

Fe/Fe₃C@N-doped porous carbon hybrids were synthesized as a robust and enhanced heterogeneous catalyst for peroxymonosulfate activation.

Insights into the influence of support and potassium or sulfur promoter on iron-based Fischer–Tropsch synthesis: understanding the control of catalytic activity, selectivity to lower olefins, and catalyst deactivation

A desired selectivity to lower olefins has been achieved by combination of K and S promoters.