The Partial Oxidation of Methane to Formaldehyde: Role of Different Crystal Planes of MoO3

Smith, Marianne R.; Ozkan, Umit S.

doi:10.1006/jcat.1993.1124

Cited by 154 publications

(86 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…According to DFTc alculations, oxygen vacancies are most likely created on bridging oxygen sites, of which the asymmetrical ones are the most favorable, as they are reduced more easily. [53][54][55] In addition, distances between those bridging sites (i.e.,O ÀMoÀO) are comparable to the distance of the vicinal OH group of the glycerolm olecule, which supports the scenario that glycerolO Hgroups are probably adsorbed on vacancies located on bridging oxygen sites. [56,57] It has been reported that the strength of Mo ÀOb onds vary between 400 and 575 kJ mol À1 .…”

Section: Implications On the Reaction Mechanismmentioning

confidence: 99%

“…Based on significant studies of selectiveo xidationr eactions that follow aM ars-vanKrevelen mechanism [31,59,60] and on the results of this study we suggest ap ossible mechanism for how the reduced molybdenum oxides promotea ctivitya nd selectivity to propene from oxygenates by ar everse Mars-vanKrevelen mechanism. Glycerol hydroxy groups may adsorb preferably on terminal or bridging oxygen defects of the catalyst surfacew here CÀOb onds are activated [54][55][56] (Scheme 7a). O atoms are attracted by the coordinately unsaturated Mo.…”

Section: Implications On the Reaction Mechanismmentioning

confidence: 99%

See 1 more Smart Citation

Exploring the Reaction Pathways of Bioglycerol Hydrodeoxygenation to Propene over Molybdena‐Based Catalysts

2017

View full text Add to dashboard Cite

The one‐step reaction of glycerol with hydrogen to form propene selectively is a particularly challenging catalytic pathway that has not yet been explored thoroughly. Molybdena‐based catalysts are active and selective to C−O bond scission; propene is the only product in the gas phase under the standard reaction conditions, and further hydrogenation to propane is impeded. Within this context, this work focuses on the exploration of the reaction pathways and the investigation of various parameters that affect the catalytic performance, such as the role of hydrogen on the product distribution and the effect of the catalyst pretreatment step. Under a hydrogen atmosphere, propene is produced primarily via 2‐propenol, whereas under an inert atmosphere propanal and glycerol dissociation products are formed mainly. The reaction most likely proceeds through a reverse Mars–van Krevelen mechanism as partially reduced Mo species drive the reaction to the formation of the desired product.

show abstract

Section: Implications On the Reaction Mechanismmentioning

confidence: 99%

Section: Implications On the Reaction Mechanismmentioning

confidence: 99%

Exploring the Reaction Pathways of Bioglycerol Hydrodeoxygenation to Propene over Molybdena‐Based Catalysts

2017

View full text Add to dashboard Cite

show abstract

“…As far as the reaction mechanism is concerned, many early studies considered that the lattice oxygen species, particularly the terminal oxygen species (i.e. Mo=O and V=O), were responsible for the activation and oxidation of methane to HCHO [39][40][41][42][43][44] . Such a mechanism may be represented by the following reactions:…”

Section: Selective Oxidation Of Methane To Formaldehyde Over Heterogementioning

confidence: 99%

Catalytic selective oxidation or oxidative functionalization of methane and ethane to organic oxygenates

Wang

Zhang

2010

Sci. China Chem.

View full text Add to dashboard Cite

Selective oxidation or oxidative functionalization of methane and ethane by both homogeneous and heterogeneous catalysis is presented concerning: (1) selective oxidation of methane and ethane to organic oxygenates by hydrogen peroxide in a water medium in the presence of homogeneous osmium catalysts, (2) selective oxidation of methane to formaldehyde over highly dispersed iron and copper heterogeneous catalysts, (3) selective oxidation of ethane to acetaldehyde and formaldehyde over supported molybdenum catalysts, and (4) oxidative carbonylation of methane to methyl acetate over heterogeneous catalysts containing dual sites of rhodium and iron.National Natural Science Foundation of China [20433030, 20625310, 20773099, 20873110]; National Basic Program of China [2005CB221408, 2010CB732303]; Key Scientific Project of Fujian [2009HZ0002-1]; Program for New Century Excellent Talents in Fujia

show abstract

“…Katalysatoren mit 1-5 Gew.-%M olybdänp roduzierten Formaldehyd als Hauptprodukt; bei hçheren Gehalten waren sie weder fürF ormaldehydnoch fürM ethanolproduktion aktiv.E sk onnte gezeigt werden, dass sich bei hçheren Konzentrationen mehr Mo-O-Mo-Brücken auf Kosten von terminalen Mo=O-Positionen bilden;d ie Letztgenannten sind wahrscheinlich fürd ie selektive Oxidation zu Formaldehyd verantwortlich. [116] Interessanterweise erhçhte sich die Ausbeute an oxygenierten Reaktionsprodukten in der Gegenwart von Wasserdampf. Dies konnte der Bildung von H 4 SiMo 12 O 40 zugeordnet werden, in deren Folge weniger Kohlenmonoxid und -dioxid produziert wurden.…”

Section: Das Aufkommen Von Molybdäntrioxid In Den 1980erunclassified

Die direkte katalytische Oxidation von Methan zu Methanol – eine kritische Beurteilung

2017

View full text Add to dashboard Cite

Es gibt vielzählige direkte, selektive Ansätze, um Methan partiell zu oxidieren, jedoch ist noch keiner von ihnen zur industriellen Reife gelangt. In diesem Zusammenhang ist die Oxidation von Methan zu Methanol eine schwierige, aber lohnende Aufgabe, da sie eine wirkungsvolle Methode ist, um das Abfackeln von Erdgas, das als Nebenprodukt in der Erdölindustrie anfällt, zu unterbinden, und zugleich die Möglichkeit bietet, Methan zu valorisieren. Dieser Aufsatz berücksichtigt die Synthese von Methanol und seinen Derivaten ausgehend von Methan durch homogen‐ und heterogenkatalytische Methoden. Er zeigt die starken Einschränkungen der direkten katalytischen Synthese von Methanol aus Methan auf und unterstreicht dabei die enorme Überlegenheit von Systemen, die Methanolderivate produzieren oder sich durch Besonderheiten wie die Verwendung von Mehrkomponenten‐Katalysatoren zur Methanolstabilisierung auszeichnen. Für die zukünftige Forschung erweist sich die Stabilisierung von Methanol in der homogenen und heterogenen Katalyse als unentbehrlich.

show abstract

The Partial Oxidation of Methane to Formaldehyde: Role of Different Crystal Planes of MoO3

Cited by 154 publications

References 0 publications

Exploring the Reaction Pathways of Bioglycerol Hydrodeoxygenation to Propene over Molybdena‐Based Catalysts

Exploring the Reaction Pathways of Bioglycerol Hydrodeoxygenation to Propene over Molybdena‐Based Catalysts

Catalytic selective oxidation or oxidative functionalization of methane and ethane to organic oxygenates

Die direkte katalytische Oxidation von Methan zu Methanol – eine kritische Beurteilung

Contact Info

Product

Resources

About