Reduction of Fe2MoO4 by hydrogen gas

Morales, Ricardo; Arvanitidis, I.; Sichen, Du; Seetharaman, Seshadri

doi:10.1007/s11663-002-0038-x

Cited by 31 publications

(33 citation statements)

References 11 publications

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“…Table 1 shows the starting materials used for the present work (reduction, reduction-carburization and reduction-nitridation). These studies can be divided in to 3 categories; (1) thermogravimetric studies, (2) fluidized bed studies and (3) thermal diffusivity measurements. In the case of thermogravimetric and fluidized bed studies systems studied were viz., Fe-Mo-O and Ni-W-O.…”

Section: Methodsmentioning

confidence: 99%

“…Complete details of the experimental set up are given elsewhere [2]. Nevertheless, the experimental conditions were adjusted as to obtain the rate of the chemical reaction as the rate controlling mechanism.…”

Section: Methods (Techniques and Procedures)mentioning

confidence: 99%

“…The sponge-like structure is the result of the removal of oxygen which increases the specific surface area. The X-ray diffraction spectrum of the same sample is given in Figure 6 [2]. Two The activation energy for Reaction (2) obtained from the regression line, in Figure 4, is 158.3 kJ/mol.…”

Section: Nonisothermal Reduction Of Fe2moo4mentioning

confidence: 97%

“…Such model was combined with the Arrehnius rate law leading to the following expression [2]: MoO 4 , respectively, k 0 is the frequency factor from the Arrhenius plot, P H 2 is the partial pressure of hydrogen, Q is the activation energy of the reaction, T is the temperature in K, and R is the gas constant. The plot of left hand side of Equation (2) as a function of 1/T is given in Figure 2.…”

Section: Fe-mo-o Systemmentioning

confidence: 99%

“…At a given temperature, the higher the heating rate the lower the reduction fraction is reached. To calculate the activation energy from the nonisothermal experimental data, a mathematical model derived earlier [8] was used. This model assumes that the rate of the chemical reaction is the rate-controlling mechanism and the reduced particles follow a shrinking core mode.…”

Section: Fe-mo-o Systemmentioning

confidence: 99%

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Gas-Solid Reaction Route toward the Production of Intermetallics from Their Corresponding Oxide Mixtures

Ahmed

Morales-Estrella

Viswanathan

et al. 2016

Metals

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Near-net shape forming of metallic components from metallic powders produced in situ from reduction of corresponding pure metal oxides has not been explored to a large extent. Such a process can be probably termed in short as the "Reduction-Sintering" process. This methodology can be especially effective in producing components containing refractory metals. Additionally, in situ production of metallic powder from complex oxides containing more than one metallic element may result in in situ alloying during reduction, possibly at lower temperatures. With this motivation, in situ reduction of complex oxides mixtures containing more than one metallic element has been investigated intensively over a period of years in the department of materials science, KTH, Sweden. This review highlights the most important features of that investigation. The investigation includes not only synthesis of intermetallics and refractory metals using the gas solid reaction route but also study the reaction kinetics and mechanism. Environmentally friendly gases like H 2 , CH 4 and N 2 were used for simultaneous reduction, carburization and nitridation, respectively. Different techniques have been utilized. A thermogravimetric analyzer was used to accurately control the process conditions and obtain reaction kinetics. The fluidized bed technique has been utilized to study the possibility of bulk production of intermetallics compared to milligrams in TGA. Carburization and nitridation of nascent formed intermetallics were successfully carried out. A novel method based on material thermal property was explored to track the reaction progress and estimate the reaction kinetics. This method implies the dynamic measure of thermal diffusivity using laser flash method. These efforts end up with a successful preparation of nanograined intermetallics like Fe-Mo and Ni-W. In addition, it ends up with simultaneous reduction and synthesis of Ni-WN and Ni-WC from their oxide mixtures in single step.

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Section: Methodsmentioning

confidence: 99%

Section: Methods (Techniques and Procedures)mentioning

confidence: 99%

Section: Nonisothermal Reduction Of Fe2moo4mentioning

confidence: 97%

Section: Fe-mo-o Systemmentioning

confidence: 99%

Section: Fe-mo-o Systemmentioning

confidence: 99%

See 3 more Smart Citations

Gas-Solid Reaction Route toward the Production of Intermetallics from Their Corresponding Oxide Mixtures

Ahmed

Morales-Estrella

Viswanathan

et al. 2016

Metals

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Hierarchically Porous Iron Alloys with High Sintering Resistance During Cyclic Steam Oxidation and Hydrogen Reduction

Pennell,

Chappuis,

Carpenter

et al. 2023

Adv Funct Materials

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Hydrogen release/storage materials for iron/air batteries are fabricated as Fe‐16Mo and Fe‐24Ni (at.%) lattices via 3D‐extrusion printing of foamed inks containing oxide microparticles, followed by H2 reduction and sintering. A hierarchical open porosity is designed: (i) channels between walls created during printing, (ii) mesopores within walls, created during ink foaming, and (iii) micropores within ligaments between mesopores, created from partial sintering metal particles and gas escape during cycling. When subjected to H2/H2O redox cycling at 800 °C, the lattices of both compositions gradually undergo sintering. The Fe‐16Mo lattice remains fully redox‐active after 50 cycles unlike the Fe‐24Ni lattice, which loses 90% of its redox capacity after 30 cycles. The increased lifetime of the Fe‐16Mo lattice is attributed to the sintering inhibition of Mo, the formation of a mixture of oxide phases in the oxidized state, and the cyclic formation of submicron Fe2Mo by reduction of MoO2 and Fe2Mo3O8. The microstructure of the foamed walls is examined throughout cycling to track changes in morphology and composition. These are correlated to volume and porosity changes in the lattice. A comparison is made to previously‐studied Fe‐Mo and Fe‐Ni freeze‐cast lamellar foams, and variations in performance are discussed in the context of the different architectures.

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Tungsten Strongly Inhibits Sintering of Porous Iron During High‐Temperature Redox Cycling

Pennell,

Chen,

Dunand

2024

Small

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Freeze‐cast Fe‐25 W (at%) lamellar foams show excellent resistance to degradation at 800 °C during steam‐hydrogen redox cycling between the metallic and oxide states, with fast reaction kinetics maintained up to at least 100 redox cycles with full Fe utilization. This very high stability stems from the sintering inhibition of W combined with the freeze‐cast architecture and the chemical vapor transport (CVT) mechanism of reduction. These three factors create a hierarchical porosity in the foam, consisting of i) macroscopic elongated channels, ii) micro‐scale sintering inhibition pores, and iii) submicron CVT pores. Microstructural characterization via SEM and EDS is combined with in situ XRD to fully explore the phase evolution and microstructural impact of W on Fe during redox cycling. Comparison with tapped Fe‐25 W (at%) powder beds reveals that the freeze‐cast channels and lamellae are not critical to the performance of the material.

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Reduction of Fe2MoO4 by hydrogen gas

Cited by 31 publications

References 11 publications

Gas-Solid Reaction Route toward the Production of Intermetallics from Their Corresponding Oxide Mixtures

Gas-Solid Reaction Route toward the Production of Intermetallics from Their Corresponding Oxide Mixtures

Hierarchically Porous Iron Alloys with High Sintering Resistance During Cyclic Steam Oxidation and Hydrogen Reduction

Tungsten Strongly Inhibits Sintering of Porous Iron During High‐Temperature Redox Cycling

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