The effect of cesium and antimony promoters on the performance of Ti-phosphate-supported vanadium(V) oxide catalysts in selective oxidation of o-xylene to phthalic anhydride

Akbari, Ali; Alavi, Seyed Mehdi

doi:10.1016/j.cherd.2015.06.030

Cited by 11 publications

(2 citation statements)

References 41 publications

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“…Scheme shows the ketone ( 3 ) and acrolein ( 5 ) intermediate fraction, reforming o -cresol ( 7 ) and acrylic acid via two parallel reactions (steps 1 and 2). , Route A includes the selective performance of VPP on oxidative valorization of o -cresol ( 7 ) to phthalic acid, as one of the best catalytic systems. − It entails the following reaction sequence: (i) activation of o -xylene ( 8 ) on a V 5+ O site by splitting of methylene C–H bonds, (ii) addition of surface oxygen atoms to create alcohol groups and then (iii) ketone groups, (iv) insertion of an oxygen atom to complete the ring and formation of phthalic anhydride, and (v) production of phthalic acid via hydration of phthalic anhydride . Route B illustrates lactic acid preparation via hydration of acrylic acid, , followed by thermal decomposition of lactic acid to acetaldehyde and formic acid at high temperature in step 3 .…”

Section: Resultsmentioning

confidence: 99%

Gas–Solid Oxidation of Unwashed Lignin to Carboxylic Acids

et al. 2020

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The availability and multifunctionality of lignin makes it a desirable, renewable alternative to petroleum for specialty and bulk chemicals. However, recovering lignin from black liquor is expensive, thus lowering its prospect as a raw material source. Direct conversion of unwashed lignin (UL) to chemicals eliminates unit operations and reaction steps, which makes it a more likely feedstock. We compared the selective oxidation of lignin and UL to produce carboxylic acids over vanadium pyrophosphate (VPP), HZSM-5 zeolite, and VPP/HZSM-5 catalysts at atmospheric pressure and varying temperature (from 140 to 650 °C), steam concentration (from 0 to 20%), and oxygen (from 0 to 15.5%). The main acids produced were formic acid, acetic acid, and malonic acid. VPP/HZSM-5 produced 5% more acids with UL compared to treated lignin. The catalytic reaction network comprises both anaerobic and aerobic pathways for oxidation-based valorization of free phenolic guaiacylglycerol-β-guaiacyl ether (GG) and non-phenolic veratrylglycerol β-guaiacyl ether (VG) model lignin compounds. The three main reaction types include selective catalytic oxidative depolymerization with interunit bond breakage (e.g., alkyl–O–aryl bonds), alkyl side chain modification (e.g., Cα–OH to CαO ketone), and aromatic ring oxidation and ring opening to produce benzoquinones and dicarboxylic acids.

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Section: Resultsmentioning

confidence: 99%

Gas–Solid Oxidation of Unwashed Lignin to Carboxylic Acids

et al. 2020

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“…In parallel, the results of cesium sorption by layered vanadium oxide provide another perspective on potential applications in catalysis or energy conversion. Some significant but non-exhaustive examples can be provided to illustrate the use of cesium-doped vanadium oxide as the active phase (or a part of it) of an efficient catalyst for catalytic decomposition or oxidation [ 66 , 67 , 68 ], as well as thin films with high electrical conductivity in perovskite solar cells [ 69 ].…”

Section: Discussionmentioning

confidence: 99%

Influence of the Nanotube Morphology and Intercalated Species on the Sorption Properties of Hybrid Layered Vanadium Oxides: Application for Cesium Removal from Aqueous Streams

et al. 2021

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The present paper examines the impact that the nanotube morphology and organic or inorganic intercalated species may have on the cesium sorption by layered vanadium oxides prepared with the use of hexadecylamine as a structure-directing agent. The hybrid material represented by a chemical formula of (V2O5)(VO2)1.03(C16H36N)1.46(H2O)x was achieved through accelerated microwave-assisted synthesis carefully optimized to ensure the best compromise between the scroll-like morphology and the hydrophobic character. To enhance its dispersibility in water, this sample was subsequently modified by progressive replacement of the C16H36N+ units by NH4+ cations. The final materials represented a stacking of lamellar sheets with a worse scroll-like morphology. Both the optimization procedure and the template removal were monitored on the basis of scanning and transmission electronic microscopy, X-ray diffraction, infra-red spectroscopy, inductively coupled plasma-optical emission spectrometry, X-ray photoelectron spectroscopy, and elemental analysis, supplemented by adequate simulations methods providing the reference IR spectra and XRD patterns for comparison or the textural parameters of the samples. The comparison of the cesium sorption from either a 4:1 ethanol–water mixture or aqueous solutions pointed toward the solubility of intercalated cations in the bulk solution as the main factor limiting their displacement from the interlayer space by the oncoming cesium ones. The sample obtained after 70% exchange with NH4+ exhibited a maximum sorption capacity of 1.4 mmol g−1 from CsNO3 aqueous solutions and its retention efficiency remained significant from low-concentration Cs solutions in river or sea water.

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