Tungsten-containing MCF silica as active and recyclable catalysts for liquid-phase oxidation of 1,3-butanediol to 4-hydroxy-2-butanone

Su, Yang; Liu, Yongmei; Wang, Lu‐Cun; Chen, Miao; Cao, Yong; Dai, Wei‐Lin; Fan, Kangnian

doi:10.1016/j.apcata.2006.09.002

Cited by 33 publications

(14 citation statements)

References 37 publications

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“…Obviously, there are no evident bands in the spectrum of SBA-15. A distinct band around 230 nm in Na 2 WO 4 corresponds to the spinel structure and isolated [WO 4 ] 2À tetrahedrons [31,42]. All W-SBA15 samples have the band mentioned above, which indicates the presence of highly dispersed tungsten species incorporated in silica framework.…”

Section: Resultsmentioning

confidence: 85%

“…Clearly, atomic ratio of tungsten was significantly reduced from 0.25% (before reaction) to 0.09% (after reaction), revealing that some tungsten species or clusters, especially crystalline WO 3 were leached from surface of SBA15, and thus induced the loss of active sites required for photocatalytic processes. In our opinion, the leaching of tungsten species from SBA15 matrix was possibly attributed to free-radical reactions during special catalytic processes triggered by photoirradiation, since it was rarely taken place in conventional catalytic reactions [31,42,46]. As a result, further work should be undertaken and focused on both the investigation of structural variation in detail after photocatalytic reactions, and structural modifications to achieve W-SBA15 derivatives with satisfactory photocatalytic performance, stability, and reusability upon visible-light irradiation for the sake of real applications in environmental remediation and protection.…”

Section: Resultsmentioning

confidence: 93%

“…An absorption band centered at 290 nm in samples from 5%W-SBA15 to 20%W-SBA15 is assigned to isolated tungsten species or low oligomeric tungsten oxide species. In addition, a broad band around 400 nm that is weak in sample 10%W-SBA15 and quite prominent in sample 20%W-SBA15, can be ascribed to the extra-framework WO 3 crystals or clusters by comparison with the spectrum of bare WO 3 [31,42]. As a result, with the increase of tungsten source content, tungsten species were able to transform from incorporated tungsten species in silica framework to WO 3 crystalline or clusters on the surface of SBA-15, in agreement with the color variation of samples and wide-angle XRD patterns.…”

Section: Resultsmentioning

confidence: 98%

“…5, a broad and strong absorption peak centered at 3427 cm À1 is indexed to the stretching vibration mode of hydrogen-bonded SiAOH moieties [43]. Bands around 1089 cm À1 is assigned to asymmetric stretching vibration of SiAOASi bond while symmetric stretching and bending vibrations give rise to bands at nearly 803 and 467 [34,42]. It is realized that the peak at 963 cm À1 is a characteristic stretching SiAO vibration mode perturbed by neighboring metal ions when the incorporation of metal ions in silica framework occurs [32,34].…”

Section: Resultsmentioning

confidence: 99%

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Synthesis, characterization, and visible-light-driven photocatalytic performance of W-SBA15

Chang

Wang

Luo

et al. 2016

Journal of Colloid and Interface Science

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a b s t r a c tA series of tungsten-containing mesoporous SBA15 with different tungsten contents were prepared through a direct co-condensation sol-gel method and then analyzed by various techniques. XRD patterns revealed that the original mesoporous morphology was maintained after introducing tungsten species and forms of tungsten species were changed from incorporated tungsten to isolated tungsten species or low oligomeric tungsten oxide species, and finally to crystalline WO 3 with the increase of tungsten precursor content, which were also proven by HRTEM images, UV-Vis DRS, and FT-IR spectra. The W-SBA15 samples exhibited satisfactory photocatalytic performance toward degradation of dye Rhodamine B (RhB) and 2,4-dichlorophenol (2,4-DCP). In particular, the best candidate, sample 10%W-SBA15 showed an apparent reaction rate constant for RhB that was nearly 10 times as high as that of bulk WO 3 . The enhancement of photocatalytic capability was attributed to the mesoporous morphology with enlarged surface areas, negatively charged surface, and favorable tungsten forms such as incorporated tungsten, isolated tungsten or low oligomeric tungsten oxide species. In addition, active radicals trapping experiments and DMPO spin-trapping ESR spectra indicated that photogenerated holes were major oxidative species during photocatalysis.

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Section: Resultsmentioning

confidence: 85%

Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Synthesis, characterization, and visible-light-driven photocatalytic performance of W-SBA15

Chang

Wang

Luo

et al. 2016

Journal of Colloid and Interface Science

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“…Numerous efforts have been focused on synthesizing materials in which the active tungsten species are well isolated and anchored on the support through W-O-Si covalent bonds. In recent years, tungsten has been incorporated into high surface area mesoporous molecular sieves, such as MCM-41 [21,[25][26][27][28][29][30][31], MCM-48 [32,33], SBA-15 [34][35][36], SBA-16 [23], HMS [37,38], MCF [39,40], KIT-5 [41], KIT-6 [24,42], and TUD-1 [43].…”

Section: Introductionmentioning

confidence: 99%

Tungsten-Based Mesoporous Silicates W-MMM-E as Heterogeneous Catalysts for Liquid-Phase Oxidations with Aqueous H2O2

et al. 2018

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Mesoporous tungsten-silicates, W-MMM-E, have been prepared following evaporation-induced self-assembly methodology and characterized by elemental analysis, XRD, N 2 adsorption, STEM-HAADF (high angle annular dark field in scanning-TEM mode), DRS UV-vis, and Raman techniques. DRS UV-vis showed the presence of two types of tungsten oxo-species in W-MMM-E samples: isolated tetrahedrally and oligomeric octahedrally coordinated ones, with the ratio depending on the content of tungsten in the catalyst. Materials with lower W loading have a higher contribution from isolated species, regardless of the preparation method. W-MMM-E catalyzes selectively oxidize of a range of alkenes and organic sulfides, including bulky terpene or thianthrene molecules, using green aqueous H 2 O 2 . The selectivity of corresponding epoxides reached 85-99% in up to 80% alkene conversions, while sulfoxides formed with 84-90% selectivity in almost complete sulfide conversions and a 90-100% H 2 O 2 utilization efficiency. The true heterogeneity of catalysis over W-MMM-E was proved by hot filtration tests. Leaching of inactive W species depended on the reaction conditions and initial W loading in the catalyst. After optimization of the catalyst system, it did not exceed 20 ppm and 3 ppm for epoxidation and sulfoxidation reactions, respectively. Elaborated catalysts could be easily retrieved by filtration and reused several times with maintenance of the catalytic behavior.

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Engineering of glycerol dehydrogenase for improved activity towards 1, 3-butanediol

Zhang

Lountos

Ching

et al. 2010

Appl Microbiol Biotechnol

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The objective of this study was to use protein engineering techniques to enhance the catalytic activity of glycerol dehydrogenase (GlyDH) on racemic 1, 3-butanediol (1, 3-BDO) for the bioproduction of the important pharmaceutical intermediate 4-hydroxy-2-butanone. Three GlyDH genes (gldA) from Escherichia coli K-12, Salmonella enterica, and Klebsiella pneumoniae MGH78578 were shuffled to generate a random mutagenesis library. The nitroblue tetrazolium/phenazine methosulfate high throughput screening protocol was used to select four chimeric enzymes with up to a 2.6-fold improved activity towards 1, 3-BDO. A rational design method was also employed to further improve the enzyme activity after DNA shuffling. Based on the homology model of GlyDH (Escherichia coli), Asp121 was predicted to influence 1, 3-BDO binding and replaced with Ala by site-directed mutagenesis. Combination of the mutations from both DNA shuffling and rational design produced the best mutant with a V (max) value of 126.6 U/mg, a 26-fold activity increase compared with that of the wild type GlyDH from E. coli.

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Tungsten-containing MCF silica as active and recyclable catalysts for liquid-phase oxidation of 1,3-butanediol to 4-hydroxy-2-butanone

Cited by 33 publications

References 37 publications

Synthesis, characterization, and visible-light-driven photocatalytic performance of W-SBA15

Synthesis, characterization, and visible-light-driven photocatalytic performance of W-SBA15

Tungsten-Based Mesoporous Silicates W-MMM-E as Heterogeneous Catalysts for Liquid-Phase Oxidations with Aqueous H2O2

Engineering of glycerol dehydrogenase for improved activity towards 1, 3-butanediol

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