Effect of pH on the Catalytic Properties of Mo–V–Te–P–O Catalysts for Selective Oxidation of Isobutane

Guan, Jingqi; Wang, Hongsu; Yang, Ying; Liu, Bo; Yu, Xiaofang; Ma, Yuanyuan; Kan, Qiubin

doi:10.1007/s10562-009-9933-y

Cited by 4 publications

(1 citation statement)

References 28 publications

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“…In this context the pH of synthesis solution is of high importance because the chemical composition and phase formation depend closely on it [10][11][12]. The catalyst precursors suggest the presence of Anderson-type heteropolyanion, (NH 4 ) 6 TeM 6 O 24 .nH 2 O in the samples prepared at pH > 3 and favouring the formation of amorphous materials at pH < 3 [12].…”

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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Section: Introductionmentioning

confidence: 99%

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

Ramli¹

2016

MJAS

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Catalysis for the synthesis of methacrylic acid and methyl methacrylate

et al. 2018

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Methyl methacrylate (MMA) is a specialty monomer for poly methyl methacrylate (PMMA) and the increasing demand for this monomer has motivated industry to develop clean technologies based on renewable resources. The dominant commercial process reacts acetone and hydrogen cyanide to MMA (ACH route) but the intermediates (hydrogen cyanide, and acetone cyanohydrin) are toxic and represent an environmental hazard. Esterification of methacrylic acid (MAA) to MMA is a compelling alternative together with ethylene, propylene, and isobutene/t-butanol as feedstocks. Partially oxidizing isobutane or 2-methyl-1,3-propanediol (2MPDO) over heteropolycompounds to MAA in a single-step is nascent technology to replace current processes. The focus of this review is on catalysts and their role in the development of processes herein described. Indeed, in some cases remarkable catalysts were studied that enabled considerable steps forward in both the advancement of catalysis science and establishing the basis for new technologies. An emblematic example is represented by Keggin-type heteropolycompounds with cesium and vanadium, which are promising catalysts to convert isobutane and 2MPDO to MAA. Renewable sources for the MMA or MAA route include acetone, isobutanol, ethanol, lactic, itaconic, and citric acids. End-of-life PMMA is expected to grow as a future source of MMA.

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Polyoxometalate catalysts with co-substituted VO²⁺and transition metals and their catalytic performance for the oxidation of isobutane

Chu

Yang

2018

Catal. Sci. Technol.

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Effect of pH on the Catalytic Properties of Mo–V–Te–P–O Catalysts for Selective Oxidation of Isobutane

Cited by 4 publications

References 28 publications

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

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

Catalysis for the synthesis of methacrylic acid and methyl methacrylate

Polyoxometalate catalysts with co-substituted VO²⁺and transition metals and their catalytic performance for the oxidation of isobutane

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Effect of pH on the Catalytic Properties of Mo–V–Te–P–O Catalysts for Selective Oxidation of Isobutane

Cited by 4 publications

References 28 publications

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

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

Catalysis for the synthesis of methacrylic acid and methyl methacrylate

Polyoxometalate catalysts with co-substituted VO2+and transition metals and their catalytic performance for the oxidation of isobutane

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Polyoxometalate catalysts with co-substituted VO²⁺and transition metals and their catalytic performance for the oxidation of isobutane