The Oxygen Isotopic Exchange Reaction on Vanadium Oxide Catalysts

Doornkamp, C.; Clement, Marjon J.; Gao, Xueqing; Deo, Goutam; Wachs, Israel E.; Ponec, V.

doi:10.1006/jcat.1999.2490

Cited by 35 publications

(35 citation statements)

References 50 publications

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“…However, the Brønsted acidity did not have 17 significant change. To summarize, the combination of V and P formed a part of stable 18 and strong Brønsted acid sites, which matched with the CO 2 , and NH 3 -TPD results. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 3.2 Effects of the amounts of V and P supported on silica in the aldol 1 condensation of AA with formalin 2…”

supporting

confidence: 80%

“…%, 16 namely the increase in P content was followed by a significant increase in VOPO 4 17 (V 5+ ) phase, which was the main catalytic active phase. In conclusion 27, 28 , the 18 presence of excessive surface P element was favorable for promoting formation of 19 VOPO 4 (V 5+ ) phase. However, a slight P-loading was play a positive role in favorable 20 for stabilizing (VO) 2 P 2 O 7 (V 4+ ), which had a deleterious effect on catalytic 21 performance.…”

mentioning

confidence: 93%

“…The valence state of vanadium in the V-P oxide 13 bifunctional catalysts was confirmed by XPS. Acetic acid (≥99.0%), formalin (37.0%), isobutyl alcohol (≥99.0%), ammonium 17 metavanadate (≥99.0%) and ammonium phosphate (≥99.0%) used were of analytical 18 grade. Oxalic acid was provided by Sinopharm Chemical Reagent Co., Ltd. SiO 2 (20 19 to 40 mesh) was purchased from Qing Dao Hailang Silica Gel Drier Factory.…”

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confidence: 99%

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Reaction of Formalin with Acetic Acid over Vanadium–Phosphorus Oxide Bifunctional Catalyst

Yang

Yao

et al. 2015

Ind. Eng. Chem. Res.

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11A new route to synthesizing acrylic acid from acetic acid and formalin by 12 one-step aldol condensation reaction was proposed and developed. V-P/ SiO 2 oxide 13 bifunctional catalysts were designed and prepared by ultrasonic impregnation method.14 The catalysts were characterized by XRD, BET, TEM, TG/DTA, and XPS, as well as 15 NH 3 , CO 2 -TPD, and pyridine-FTIR methods. Catalytic performance was evaluated 16 using a fixed-bed tubular microreactor operating with a CH 3 COOH/HCHO (HAc/FA) 17 molar ratio of 10 under atmospheric pressure. Influences of the balance between 18 acidic and alkaline sites, as well as ratio of V 4+ and V 5+ , on catalyst activity were 19 further studied. Reaction parameters were systemically optimized. Through a series of 20 comparisons, V-P/SiO 2 binary oxide catalyst with a bulk density ratio of 1:2 was 21 selected. 1

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confidence: 80%

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confidence: 93%

mentioning

confidence: 99%

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Reaction of Formalin with Acetic Acid over Vanadium–Phosphorus Oxide Bifunctional Catalyst

Yang

Yao

et al. 2015

Ind. Eng. Chem. Res.

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“…The role of TiO 2 in V 2 O 5 /TiO 2 catalyst has also been studied by several authors [27][28][29][30] and is well reviewed by Wachs and Weckhuysen [27]. The terminal V=O bonds have been proposed by many investigators to contain critical oxygen involved in hydrocarbon oxidation reactions over supported vanadia catalysts [31].…”

Section: Selective Oxidation Of H 2 Smentioning

confidence: 98%

Selective catalytic oxidation of H2S using nonhydrolytic vanadia-titania xerogels

Cho

Kim

Park

et al. 2009

Korean J. Chem. Eng.

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A series of vanadia-titania (V-Ti) xerogel catalysts were prepared by nonhydrolytic sol-gel method. These catalysts showed much higher surface area and total pore volumes than the conventional V 2 O 5 -TiO 2 xerogel. Two species of surface vanadium in the xerogel catalysts were identified by Raman measurements: monomeric vanadyl and polymeric vanadates. The selective oxidation of hydrogen sulfide in the presence of excess water and ammonia was studied over these catalysts. Xerogel catalysts from the nonhydrolytic method showed very high conversion of H 2 S without harmful emission of SO 2 . The conversion of H 2 S increased with increasing vanadia loading up to 10V-Ti; however, it decreased at higher vanadia loading (12V-Ti and 18V-Ti) probably due to the formation of crystalline V 2 O 5 .

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“…Therefore, monolayer coverage or maximum dispersion limit is a critical parameter that allows distinguishing between two-dimensional molecularly dispersed surface metal oxide species and the three-dimensional NPs present in supported metal oxide materials. For the purposes of simplifying and focusing the discussion, only SiO 2 -supported metal oxide catalysts at submonolayer coverages will be discussed in this chapter since the catalysis literature has demonstrated that only isolated surface metal oxide species are present at low coverage for supported MO x /SiO 2 catalysts [14,[38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56].…”

Section: Introductionmentioning

confidence: 99%