In situ DRIFTS studies of high-temperature water-gas shift reaction on chromium-free iron oxide catalysts

Boudjemaa, Amel; Daniel, Cécile; Mirodatos, C.; Trari, M.; Auroux, A.; Bouarab, R.

doi:10.1016/j.crci.2010.11.007

Cited by 33 publications

(25 citation statements)

References 24 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is noteworthy that the peak intensity of this formate species is much higher than that of the carbonate species. Yet, another species with corresponding peaks at 3046 and 3140 cm −1 matched well with those of hydroxyl groups, as reported in the literature 50 . It should be noted that no obvious peaks could be detected in the range of 2000–1800 cm −1 for Ni@SiXNS-EtOH, which reveals the essential absence of bridging CO; this is likely because Ni nanoparticles in the catalyst are trapped between sheets of SiXNS, thus decreasing the chance for the bonding of CO molecules to multiple Ni atoms.…”

Section: Resultssupporting

confidence: 87%

Nickel@Siloxene catalytic nanosheets for high-performance CO2 methanation

et al. 2019

View full text Add to dashboard Cite

Two-dimensional (2D) materials are of considerable interest for catalyzing the heterogeneous conversion of CO 2 to synthetic fuels. In this regard, 2D siloxene nanosheets, have escaped thorough exploration, despite being composed of earth-abundant elements. Herein we demonstrate the remarkable catalytic activity, selectivity, and stability of a nickel@siloxene nanocomposite; it is found that this promising catalytic performance is highly sensitive to the location of the nickel component, being on either the interior or the exterior of adjacent siloxene nanosheets. Control over the location of nickel is achieved by employing the terminal groups of siloxene and varying the solvent used during its nucleation and growth, which ultimately determines the distinct reaction intermediates and pathways for the catalytic CO 2 methanation. Significantly, a CO 2 methanation rate of 100 mmol g Ni −1 h −1 is achieved with over 90% selectivity when nickel resides specifically between the sheets of siloxene.

show abstract

Section: Resultssupporting

confidence: 87%

Nickel@Siloxene catalytic nanosheets for high-performance CO2 methanation

et al. 2019

View full text Add to dashboard Cite

show abstract

“…38,55 The complex absorption in the 2800-2400 cm -1 region is probably due to a Fermi resonance of the overtone of the OHδ vibration mode with the CHstretching modes at 2971, 2929, and 2863 cm -1 (CH 3 (as), CH 2 (as) and CH 3 (s) modes of the ethoxide species Some remarkable differences between the DRIFTS spectra of samples are observed when the temperature is increased ( Figure 6); acetate bands appear (at 1334, 1439, 1590 cm −1 for the CH3 δ, (OCOν(s), and OCOν(as) vibrations, respectively). 60 The DRIFT spectra obtained on Mn 0.6 Fe 2.4 O 4 (Fig 6-D), also exhibit the bands for acetate species, formed by the reaction of ethoxy species with surface oxygen (1598, 1555, 1433 and 1334 cm -1 ). 59 These species could further produce CO 2 , which is detected as the doublet at the 2358-2338 cm -1 region and corresponds to adsorbed and/or gaseous CO 2 rotation vibration P and R bands.…”

Section: Surface Characterization: Drift Spectroscopymentioning

confidence: 81%

Towards an improved process for hydrogen production: the chemical-loop reforming of ethanol

Vozniuk

Agnoli²,

Artiglia³

et al. 2016

Green Chem.

View full text Add to dashboard Cite

International audienceM-modified ferrospinels with the formula M0.6Fe2.4Oy (M = Co, Mn or Co/Mn) were employed as ionic oxygen and electron carrier materials for an alternative sustainable route to produce hydrogen via chemical-loop reforming of ethanol. The new materials were tested in terms of both redox properties and catalytic activity to generate hydrogen by oxidation with steam, after a reductive step carried out with ethanol. In addition, the research includes in situ DRIFTS and in situ XPS studies that allowed the extraction of information at the molecular level and following surface changes within the reduction/re-oxidation processes during ethanol chemical-loop reforming. It was found that Co(II)-incorporation in spinels effectively improves decomposition/oxidation of ethanol, however a greater amount of coke is accumulated. On the other hand, addition of Mn(II) into the system helps to significantly reduce the amount of coke and hence to avoid fast deactivation of the material. Thus, the behavior of Co0.3Mn0.3Fe2.4Oy was shown to be the most promising one, as this material forms less coke during the reduction step, and consequently less COx is generated during the re-oxidation step with water, nevertheless a high hydrogen yield is maintained

show abstract

“…By choosing MgO, TiO 2 , and SiO 2 to support iron oxide in this section, it was expected that the large variety of acid-base strengths of MgO (basic support), TiO 2 (amphiprotic support), or SiO 2 (acidic support) important in determining catalytic activity could be realized. In a previous work [12], we have shown that the most active system is the catalyst containing MgO as a support. Fe 2 O 3 /MgO is 12 times more active than Fe 2 O 3 /TiO 2 , 21 times more active than the unsupported catalyst, and 100 times more active than Fe…”

Section: Fe-mg Systemsmentioning

confidence: 95%

“…Boudjemaa et al [3] have reported that magnesium could be a good candidate to replace chromium in iron-based catalysts since Mg-rich catalysts are more active than Cr-promoted ones. By adding MgO to Fe 2 O 3 [12], it was found that the Fe 2 O 3 -MgO basic catalyst is 100 times more active than the acidic catalyst Fe 2 O 3 /SiO 2 and a direct relation between catalytic activity and acid-base properties of catalysts is established.…”

Section: Journal Of Catalystsmentioning

confidence: 99%

Hydrogen Production from the Water-Gas Shift Reaction on Iron Oxide Catalysts

Bouarab

Bennici

Mirodatos

et al. 2014

Journal of Catalysts

View full text Add to dashboard Cite

Unsupported and supported iron oxide catalysts were prepared by incipient wetness impregnation method and studied in the water-gas shift reaction (WGSR) in the temperature range 350–450°C. The techniques of characterization employed were BET, X-ray diffraction, acid-base measurements by microcalorimetry and in situ diffuse reflectance infrared Fourier transform spectroscopy. MgO, TiO2, or SiO2 was added in order to (i) obtain a catalyst exempt of chromium oxide and (ii) study the effect of their acid-base properties on catalytic activity of Fe2O3. X-ray diffraction studies, and calorimetric and diffuse reflectance infrared Fourier transform measurements reveal a complete change in the physicochemical properties of the iron oxide catalyst after MgO addition due to the formation of the spinel oxide phase. These results could indicate that the MgFe2O4 phase stabilizes the reduced iron phase, preventing its sintering under realistic WGSR conditions (high H2O partial pressures).

show abstract

In situ DRIFTS studies of high-temperature water-gas shift reaction on chromium-free iron oxide catalysts

Cited by 33 publications

References 24 publications

Nickel@Siloxene catalytic nanosheets for high-performance CO2 methanation

Nickel@Siloxene catalytic nanosheets for high-performance CO2 methanation

Towards an improved process for hydrogen production: the chemical-loop reforming of ethanol

Hydrogen Production from the Water-Gas Shift Reaction on Iron Oxide Catalysts

Contact Info

Product

Resources

About