Studies on influence of hydrogen and carbon monoxide concentration on reduction progression behavior of molybdenum oxide catalyst

Samsuri, Alinda; Latif, Mohd Nor; Shamsuddin, Mohd Razali; Salleh, Fairous; Tahari, Maratun Najiha Abu; Saharuddin, Tengku Shafazila Tengku; Dzakaria, Norliza; Yarmo, Mohd Ambar

doi:10.1016/j.ijhydene.2020.08.214

Cited by 11 publications

(6 citation statements)

References 39 publications

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“…There is only one broad reduction peak centered at 650°C for the H 2 ‐TPR profile of MoO 3 − 1 sample, which was assigned to the deep reduction of Mo 6+ to Mo 0 (Mo 6+ → Mo 0 ) and of Mo 5+ to Mo 0 (Mo 5+ → Mo 0 ) on MoO 3 − 1 . [ 33 ] Although MoO 3 − 2 and MoO 3 − 3 samples also showed a broad reduction peak, two shoulders were observed. The shoulder at low temperature should be assigned to the reduction of the Mo 6+ to Mo 4+ species, [ 34,35 ] and the shoulder at high temperature should be associated with the reduction of the Mo 4+ to Mo 0 and the deep reduction of the Mo 5+ species (Mo 5+ → Mo 0 ).…”

Section: Resultsmentioning

confidence: 99%

“…Mo 0 ) on MoO 3 À 1 . [33] Although MoO 3 À 2 and MoO 3 À 3 samples also showed a broad reduction peak, two shoulders were observed. The shoulder at low temperature should be assigned to the reduction of the Mo 6+ to Mo 4+ species, [34,35] and the shoulder at high temperature should be associated with the reduction of the Mo 4+ to Mo 0 and the deep reduction of the Mo 5+ species (Mo 5+ !…”

Section: Catalyst Characterizationmentioning

confidence: 95%

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Molybdenum oxides catalyzed the N,N‐dimethylamination of alcohols with N,N‐dimethylformamide for direct synthesis of tertiary amines

Zhou

Liu

Zhang

et al. 2023

Applied Organom Chemis

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Molybdenum oxides (MoO3 − x, x = 1, 2, and 3) with three types of morphologies were prepared and applied to the reaction of benzyl alcohol with dimethylformamide (DMF) for synthesis of tertiary amines. The MoO3 − 1 catalyst prepared by direct calcination exhibited high activity and tertiary amines selectivity in the N,N‐dimethylamination of benzyl alcohol under the reaction conditions at 150°C for 12 h using DMF as a methylating agent and solvent, as compared to MoO3 − 2 and MoO3 − 3 catalysts. This feature was ascribed to the high proportion of surface chemisorbed oxygen for MoO3 − 1 sample, which can promote the adsorbed benzyl alcohol transformation into benzaldehyde. The MoO3 − 1 catalyst was also found to be reusable in five consecutive runs without a significant decrease in catalytic activity. In addition, control experiments showed two parallel reaction routes in this catalytic system. One route is the reaction of benzaldehyde intermediate and DMF to form tertiary amines (Route I); the other route is that benzyl formate intermediate reacted with DMF (Route II), which has not been reported before and specifically involves the esterification of benzyl alcohol with formic acid from DMF decomposition to form benzyl formate.

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Section: Resultsmentioning

confidence: 99%

Section: Catalyst Characterizationmentioning

confidence: 95%

Molybdenum oxides catalyzed the N,N‐dimethylamination of alcohols with N,N‐dimethylformamide for direct synthesis of tertiary amines

Zhou

Liu

Zhang

et al. 2023

Applied Organom Chemis

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“…The absence of the diffraction peaks indicates that it may be highly dispersed within the amorphous phase of the La 2 O 3 ‐Al 2 O 3 composite 21,22 . The extra diffraction peak at 2θ° of 23.90 and 26.94 °is attributed to the presence of orthorhombic phase of molybdenum oxide 23,24 …”

Section: Resultsmentioning

confidence: 99%

Kinetic modeling of oxidative dehydrogenation of propane with CO₂ over MoO_x/La₂O₃–Al₂O₃ in a fluidized bed

et al. 2022

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A 4‐step kinetic model of CO2‐assisted oxidative dehydrogenation (ODH) of propane to C2/C3 olefins over a novel MoOx/La2O3–γAl2O3 catalyst was developed. Kinetic experiments were conducted in a CREC Riser Simulator at various reaction temperatures (525–600 °C) and times (15–30 s). The catalyst was highly selective towards propylene at all combinations of the reaction conditions. Langmuir‐Hinshelwood type kinetics were formulated considering propane ODH, uni‐ and bimolecular cracking of propane to produce a C1‐C2 species. It was found that the one site type model adequately fitted the experimental data. The activation energy for the formation of propylene (67.8 kJ/mol) is much lower than that of bimolecular conversion of propane to ethane and ethylene (303 kJ/mol) as well as the direct cracking of propane to methane and ethylene (106.7 kJ/mol). The kinetic modeling revealed the positive effects of CO2 towards enhancing the propylene selectivity over the catalyst.

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“…Different from MoO 2 , these suboxide MoO 3−x species are amorphous and not detected by XRD, which is also reported before. 49,50 The semiquantitative analysis of these surface Mo species is also given in Table S1. It is found that Mo 4+ (presented as MoS 2 or MoO 2 ) species is gradually decreased with the increase in oxygen etching temperature.…”

Section: ■ Introductionmentioning

confidence: 99%

Facile Synthesis of Highly Defective MoS_xO_y Catalysts by Oxygen Etching-Reduction for Efficient m-Cresol Hydrodeoxygenation

Zhou

Zhang

Yang

2023

Ind. Eng. Chem. Res.

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The hydrodeoxygenation of phenolics is one of the key processes in lignin upgrading to fuel or aromatic products. MoS 2 -based catalysts show potential application in this reaction, and the defects are known to play an important role in phenolic C− O bond activation. However, the preparation of defective MoS 2 -based catalysts is usually complex. In this work, we report a facile synthesis of highly defective MoS x O y catalysts from MoS 2 by the oxygen etching-reduction. With the increase in etching temperature, the structure evolution of catalysts goes through the 2D nanosheet, imperfect nanorod/nanotube to large bulk particle. After H 2 reduction, two types of defects are determined on the surface, including undercoordinated Mo 4+∼3+ from the MoS 2 phase and Mo 5+ from MoO x . The Mo 5+ site is found to be more effective than Mo 4+∼3+ in phenolic C−O activation, while the MoS 2 phase is stronger in H 2 dissociation than MoO x . On MoS x O y -350, MoS 2 and MoO x phases are intimately contacted in the nanoscale, leading to a synergistic effect between Mo 5+ and MoS 2 , thus showing the highest activity in the m-cresol HDO reaction.

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Studies on influence of hydrogen and carbon monoxide concentration on reduction progression behavior of molybdenum oxide catalyst

Cited by 11 publications

References 39 publications

Molybdenum oxides catalyzed the N,N‐dimethylamination of alcohols with N,N‐dimethylformamide for direct synthesis of tertiary amines

Molybdenum oxides catalyzed the N,N‐dimethylamination of alcohols with N,N‐dimethylformamide for direct synthesis of tertiary amines

Kinetic modeling of oxidative dehydrogenation of propane with CO₂ over MoO_x/La₂O₃–Al₂O₃ in a fluidized bed

Facile Synthesis of Highly Defective MoS_xO_y Catalysts by Oxygen Etching-Reduction for Efficient m-Cresol Hydrodeoxygenation

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Studies on influence of hydrogen and carbon monoxide concentration on reduction progression behavior of molybdenum oxide catalyst

Cited by 11 publications

References 39 publications

Molybdenum oxides catalyzed the N,N‐dimethylamination of alcohols with N,N‐dimethylformamide for direct synthesis of tertiary amines

Molybdenum oxides catalyzed the N,N‐dimethylamination of alcohols with N,N‐dimethylformamide for direct synthesis of tertiary amines

Kinetic modeling of oxidative dehydrogenation of propane with CO2 over MoOx/La2O3–Al2O3 in a fluidized bed

Facile Synthesis of Highly Defective MoSxOy Catalysts by Oxygen Etching-Reduction for Efficient m-Cresol Hydrodeoxygenation

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Product

Resources

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Kinetic modeling of oxidative dehydrogenation of propane with CO₂ over MoO_x/La₂O₃–Al₂O₃ in a fluidized bed

Facile Synthesis of Highly Defective MoS_xO_y Catalysts by Oxygen Etching-Reduction for Efficient m-Cresol Hydrodeoxygenation