Activity, Selectivity and Initial Degradation of Iron Molybdate in the Oxidative Dehydrogenation of Ethanol

Oefner, Niklas; Heck, Franziska; Dürl, Marcel; Schumacher, Leon; Siddiqui, Humera Khatoon; Kramm, Ulrike I.; Heß, Christian; Möller, Angela; Albert, Barbara; Etzold, Bastian J. M.

doi:10.1002/cctc.202101219

Cited by 9 publications

(11 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the selectivity is slightly lower, while diethyl ether is the main side product (S DEE ≈ 7%). Overall, the initial activity upon heating is comparable with common catalysts obtained from precipitates . Above 300 °C, almost complete ethanol conversion occurs, while CO x (for simplicity reasons, we give the combined value for separately detected CO and CO 2 ) and ethene production increase at the expense of acetaldehyde.…”

Section: Resultsmentioning

confidence: 56%

“…Employing the aforementioned solid-state protocols enables us to correlate defect concentrations with the sample’s history and the physical properties obtained from in-depth X-ray diffraction, 57 Fe-Mössbauer spectroscopy, and magnetic measurements. Proof of concept is the catalytic performance of selected Fe 2 (MoO 4 ) 3 samples, using the recently demonstrated ethanol ODH protocol …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Insights into the Role of Defects in Fe₂(MoO₄)₃ Catalysts

et al. 2023

Self Cite

View full text Add to dashboard Cite

The catalytic activity and selectivity of Fe 2 (MoO 4 ) 3 obtained from solidstate synthesis protocols is investigated for the oxidative dehydrogenation (ODH) of ethanol to acetaldehyde. While Fe 2 (MoO 4 ) 3 annealed in a MoO 3 atmosphere is found to be inactive, ball-milling of such solid-state synthesis precursors leads to an increase in activity, which cannot be attributed purely to the change in the specific surface area nor to a geometric effect of smaller particles. In a systematic study of the synthesis of Fe 2 O 3 -free Fe 2 (MoO 4 ) 3 samples, the correlation of ball-milling time, defect concentration, and catalytic activity is presented. In-depth X-ray diffraction studies, magnetic susceptibility, and 57 Fe-Mossbauer spectroscopic measurements disclose characteristic signatures of the defect sites in the solid materials introduced by ball-milling and indicate: (i) MoO 3enriched amorphous layers of variable thickness (shell-like) and (ii) crystalline bulk defects corresponding to a reduction in the molar volume of the solid. The onset of recrystallization processes sets in around 300 °C and is accompanied by an enhanced MoO 3 mobility in the particles, which adds to an increase in activity and a decreasing selectivity under catalytic conditions. Accordingly, the defects associated with the decreasing amorphous fraction are converted to crystalline bulk defects, which are monitored by the magnetic hyperfine field distribution of the respective Fe sites. Overall, this study shows the importance of the amorphous layer thickness with a sufficient defect concentration and of the bulk defects' contribution to the chemical gradients, important for the MoO 3 mobility and reduction of the MoO 3 loss as a volatile species at the solid/gas phase boundary in ODH catalysis.

show abstract

Section: Resultsmentioning

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Insights into the Role of Defects in Fe₂(MoO₄)₃ Catalysts

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…Due to this attractiveness, different catalyst systems have been studied for ethanol ODH . So far, the main classes of investigated catalysts have been supported metal oxides, mainly supported VO x , − supported metal catalysts, , carbon-based catalysts, and mixed metal oxides. ,, …”

Section: Introductionmentioning

confidence: 99%

MXene Aerogel Derived Ultra-Active Vanadia Catalyst for Selective Conversion of Sustainable Alcohols to Base Chemicals

Oefner

Shuck

Schumacher

et al. 2023

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

Selective oxidation reactions are an important class of the current chemical industry and will be highly important for future sustainable chemical production. Especially, the selective oxidation of primary alcohols is expected to be of high future interest, as alcohols can be obtained on technical scales from biomass fermentation. The oxidation of primary alcohols produces aldehydes, which are important intermediates. While selective methanol oxidation is industrially established, the commercial catalyst suffers from deactivation. Ethanol selective oxidation is not commercialized but would give access to sustainable acetaldehyde production when using renewable ethanol. In this work, it is shown that employing 2D MXenes as building blocks allows one to design a nanostructured oxide catalyst composed of mixed valence vanadium oxides, which outperforms on both reactions known materials by nearly an order of magnitude in activity, while showing high selectivity and stability. The study shows that the synthesis route employing 2D materials is key to obtain these attractive catalysts. V 4 C 3 T x MXene structured as an aerogel precursor needs to be employed and mildly oxidized in an alcohol and oxygen atmosphere to result in the aspired nanostructured catalyst composed of mixed valence VO 2 , V 6 O 13 , and V 3 O 7 . Very likely, the bulk stable reduced valence state of the material together coupled with the nanorod arrangement allows for unprecedented oxygen mobility as well as active sites and results in an ultra-active catalyst.

show abstract

“…[1] In ethanol oxidation reaction (EOR) that takes place in direct ethanol fuel cells [2][3][4][5] or in hydrogen production via ethanol steam reforming, [6][7][8][9][10][11] ethanol dehydrogenation is the first step in the complex reaction network and therefore has been an active area of research. [12,13] Additionally, ethanol dehydrogenation is the first elementary reaction and plays important roles in the synthesis of acetaldehyde, [14][15][16][17][18] ethyl acetate, [19][20][21] butadiene, [22,23] butanol, [24][25][26] polyvinyl alcohol, [27] aromatic alcohols, [28] and bio-fuels. [29,30] Different degree of ethanol dehydrogenation is involved depending on the overall reaction of interest.…”

Section: Introductionmentioning

confidence: 99%

“…For instance, investigating dehydrogenation is critical for the advancement of energy research toward sustainability and feasible applications [1] . In ethanol oxidation reaction (EOR) that takes place in direct ethanol fuel cells [2–5] or in hydrogen production via ethanol steam reforming, [6–11] ethanol dehydrogenation is the first step in the complex reaction network and therefore has been an active area of research [12,13] . Additionally, ethanol dehydrogenation is the first elementary reaction and plays important roles in the synthesis of acetaldehyde, [14–18] ethyl acetate, [19–21] butadiene, [22,23] butanol, [24–26] polyvinyl alcohol, [27] aromatic alcohols, [28] and bio‐fuels [29,30] .…”

Section: Introductionmentioning

confidence: 99%

Insights and Activation Energy Surface of the Dehydrogenation of C₂H_xO Species in Ethanol Oxidation Reaction on Ir(100)

Wang

2022

ChemPhysChem

View full text Add to dashboard Cite

Dehydrogenation of an organic compound is the first and the most fundamental elementary reaction in many organic reactions. In ethanol oxidation reaction (EOR) to form CO 2 , there are a total of 46 pathways in C 2 H x O (x = 1-6) species leading to the removal of all six hydrogen atoms in five CÀ H bonds and one OÀ H bond. To investigate the degree of dehydrogenation in EOR under operando conditions, we performed density function theory (DFT) calculations to study 28 dehydrogenation steps of C 2 H x O on Ir(100). An activation energy surface was then constructed and compared with that of the CÀ C bond cleavages to understand the importance of the degree of dehydrogenation in EOR. The results show that there are likely 28 dehydrogenations in EOR under fuel cell temperatures and the last two hydrogens in C 2 H 2 O are less likely cleaved. On the other hand, deep dehydrogenation including 45 dehydrogenations can occur under ethanol steam reforming conditions.

show abstract

Activity, Selectivity and Initial Degradation of Iron Molybdate in the Oxidative Dehydrogenation of Ethanol

Cited by 9 publications

References 50 publications

Insights into the Role of Defects in Fe₂(MoO₄)₃ Catalysts

Insights into the Role of Defects in Fe₂(MoO₄)₃ Catalysts

MXene Aerogel Derived Ultra-Active Vanadia Catalyst for Selective Conversion of Sustainable Alcohols to Base Chemicals

Insights and Activation Energy Surface of the Dehydrogenation of C₂H_xO Species in Ethanol Oxidation Reaction on Ir(100)

Contact Info

Product

Resources

About

Activity, Selectivity and Initial Degradation of Iron Molybdate in the Oxidative Dehydrogenation of Ethanol

Cited by 9 publications

References 50 publications

Insights into the Role of Defects in Fe2(MoO4)3 Catalysts

Insights into the Role of Defects in Fe2(MoO4)3 Catalysts

MXene Aerogel Derived Ultra-Active Vanadia Catalyst for Selective Conversion of Sustainable Alcohols to Base Chemicals

Insights and Activation Energy Surface of the Dehydrogenation of C2HxO Species in Ethanol Oxidation Reaction on Ir(100)

Contact Info

Product

Resources

About

Insights into the Role of Defects in Fe₂(MoO₄)₃ Catalysts

Insights into the Role of Defects in Fe₂(MoO₄)₃ Catalysts

Insights and Activation Energy Surface of the Dehydrogenation of C₂H_xO Species in Ethanol Oxidation Reaction on Ir(100)