A new approach to the preparation of MoVNbTe mixed oxide catalysts for the oxidation of propane to acrylic acid

Tu, X.; Furuta, Naomasa; Sumida, Yuuichi; Takahashi, Mamoru; Niiduma, Hiroshi

doi:10.1016/j.cattod.2006.05.059

Cited by 22 publications

(10 citation statements)

References 16 publications

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“…The M2 phase was also reported to serve as a tellurium reservoir for the M1 phase [22,23]. The effects of different preparation methods [12][13][14], synthesis conditions [24][25][26] and precursors used [27][28][29] are also only fragmentary known. Well-defined synthesis procedures allow the synthesis of materials with reproducible catalytic properties, but variations in the procedure still lead to catalysts with so far unpredictable catalytic properties.…”

Section: Introductionmentioning

confidence: 99%

On the Role of the Vanadium Distribution in MoVTeNbO x Mixed Oxides for the Selective Catalytic Oxidation of Propane

2011

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The selective oxidation of propane to acrylic acid is studied over a series of nearly pure M1-phase MoVTeNbO x catalysts. Quantitative analysis of the reaction network shows that the ratio of the rate constants for propane oxidative dehydrogenation to propene and for the further oxidation of propene is constant. The rates towards acrolein and acetone, however, vary subtly with the concentration of vanadium and the location of its substitution. The reaction of acrolein to acetic acid and carbon oxides, associated with accessible metal cations, contributes twothirds towards the non-selective pathway. The other third is associated with acetone formation. Vanadium is first substituted selectively at sites that are inactive for propane activation. Depending on the selectivity of this substitution two groups of materials have been identified, which show a distinctly different dependence on the concentration of vanadium. Statistic distribution of vanadium in the M1 phase appears to be the most promising strategy to improve the performance of MoVTeNbO x catalysts for a given vanadium concentration.

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Section: Introductionmentioning

confidence: 99%

On the Role of the Vanadium Distribution in MoVTeNbO x Mixed Oxides for the Selective Catalytic Oxidation of Propane

2011

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“…As the pH of synthesis solution increases, the metal oxide peaks become apparent. All of the other three samples (MVTN 3p , MVTN 5p , and MVTN 7p ) exhibited sharp peaks at 2θ = 10.3°, 12.5°, 13 2 O was formed in samples prepared at pH 3.0-4.5 whereby at pH < 3 the heteropolyanion partially decomposed with the formation of mostly amorphous materials and at a very low pH 1.0-1.5 indicates the present of polyoxovanadates in the precursors [12]. Therefore, as observed in this work at low pH the crystallinity of heteropolyanion compounds decreases and amorphous materials are observed due to the partial incorporation of heteroatoms or the heteroatoms are highly dispersed on the compounds.…”

Section: Results and Discussion Physicochemical Properties Of Movtenbmentioning

confidence: 99%

“…The catalyst is reportedly the most effective catalyst system for the vapour phase catalytic oxidation of propane to form acrylic acid [1][2][3][4][5][6]. It is because the catalyst contains necessary active sites which is fundamental in propane oxidation [7].…”

Section: Introductionmentioning

confidence: 99%

EFFECT OF pH ON THE PHYSICOCHEMICAL PROPERTIES AND REDUCIBILITY OF MoVTeNbOx CATALYSTS

Ramli¹

2016

MJAS

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A range of MoVTeNbOx catalysts were synthesised by slurry method assisted with a microwave irradiation. The pH of the synthesis solution was varied at pH = 1, 3, 5, and 7 and the obtained solid were calcined in air at 553 K for 1 hour and followed in N 2 at 873 K for 2 hours. The calcined samples were characterised and their reduction properties were evaluated. The pH of the synthesis solution was shown to affect the physicochemical properties where the formation of orthorhombic M1 phase was obtained for catalysts prepared at pH 1 and 3. The reducibility of the catalyst is improved for catalyst prepared at pH 3 as compared to those prepared at pH 1. Although higher synthesised pH (5 and 7) gave much higher reducibility of the metal oxides, however the removable oxygen could be of the unselective ones.Keywords: MoVTeNbOx catalysts, pH, reducibility, propane, acrylic acid Abstrak Satu siri mangkin MoVTeNbOx telah disintesis menggunakan kaedah buburan dibantu oleh radiasi gelombang mikro. Nilai pH bagi larutan sintesis telah dikaji pada pH = 1, 3, 5, dan 7 dan pepejal yang diperolehi telah dikalsin dalam udara pada 553 K selama 1 jam dan diikuti dalam nitrogen pada 873 K selama 2 jam. Sampel terkalsin telah dicirikan dan sifat kebolehturunan telah dikaji. Di dapati, pH bagi larutan sintesis memberi kesan kepada ciri fizikokimia di mana pembentukan fasa ortorombik M1 telah terjadi bagi mangkin yang disediakan pada pH 1 dan 3. Kebolehturunan mangkin ini dipertingkatkan bagi mangkin yang disediakan pada pH 3 berbanding yang disediakan pada pH 1. Walaupun mangkin yang disediakan pada pH yang lebih tinggi (5 dan 7) memberikan kebolehturunan logam oksida lebih tinggi, namun penyingkiran oksigen mungkin menjadi tidak selektif.Kata kunci: mangkin MoVTeNbOx, pH, kebolehturunan, propana, asid akrilik IntroductionMoVTeNbOx is a quaternary mixed metal oxide catalyst consists of four different elements which are molybdenum, vanadium, tellurium and niobium. The catalyst is reportedly the most effective catalyst system for the vapour phase catalytic oxidation of propane to form acrylic acid [1][2][3][4][5][6]. It is because the catalyst contains necessary active sites which is fundamental in propane oxidation [7]. The active MoVTeNbOx system possesses two crystalline phases which are orthorhombic M1 phase, Te 2 M 20 O 57 (M = Mo, V, Nb), and hexagonal M2 phase, Te 0.33 MO 3.33 (M = Mo, V, Nb) [8]. The significant difference exists among these two phases is that the M1 phase contains V 5+ centres, as an agent for propane activation [4,7]. Meanwhile, M2 is incapable of activating propane, but it does convert

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“…Another approach is by using a slurry method [29,30] on the basis of a non-solution precursor. This condition inevitably contributes to the multiphase MoVTeNbOx system in which the species is always present in different valence states due to its non-equilibrium state.…”

Section: -2506mentioning

confidence: 99%

ENHANCED REDUCIBILITY OF Mg-DOPED MoVTeNbOx MIXED OXIDE CATALYSTS FOR PROPANE OXIDATION REACTION

Ramli¹

2016

MJAS

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A series of magnesium-doped MoVTeNbOx (MVTN-Mg) catalysts, as well as undoped sample (MVTN) was prepared by microwave-assisted slurry method followed by calcination in nitrogen at 873 K for 2 hours. The catalysts were further posttreated in aqueous hydrogen peroxide. The physicochemical properties of the catalysts were investigated using X-ray diffraction (XRD), surface area measurement using Brunauer

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A new approach to the preparation of MoVNbTe mixed oxide catalysts for the oxidation of propane to acrylic acid

Cited by 22 publications

References 16 publications

On the Role of the Vanadium Distribution in MoVTeNbO x Mixed Oxides for the Selective Catalytic Oxidation of Propane

On the Role of the Vanadium Distribution in MoVTeNbO x Mixed Oxides for the Selective Catalytic Oxidation of Propane

EFFECT OF pH ON THE PHYSICOCHEMICAL PROPERTIES AND REDUCIBILITY OF MoVTeNbOx CATALYSTS

ENHANCED REDUCIBILITY OF Mg-DOPED MoVTeNbOx MIXED OXIDE CATALYSTS FOR PROPANE OXIDATION REACTION

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