Photodeposited Pd nanoparticle catalysts supported on photoactivated TiO2 nanofibers

Obuya, Emilly A.; Harrigan, William L.; Andala, Dickson; Lippens, Jennifer L.; Keane, Thomas C.; Jones, Wayne E.

doi:10.1016/j.molcata.2011.03.016

Cited by 34 publications

(14 citation statements)

References 32 publications

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“…After sintering at N 2 or NH 3 , the TiO 2 nanofibers contained carbon but not nitrogen. The presence of carbon peaks may be attributed to the residual organics from the incomplete combustion of PVP during calcination [17,18]. The structure of fibers did not change with increasing temperature, as shown in Figure 3C,D.…”

Section: Resultsmentioning

confidence: 99%

The effects of atmosphere and calcined temperature on photocatalytic activity of TiO2 nanofibers prepared by electrospinning

Fang

Tang

et al. 2013

Nanoscale Res Lett

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TiO2-based nanofibers were synthesized using a sol–gel method and electrospinning technique. The as-spun composite fibers were heat-treated at different temperatures (500°C, 550°C, 600°C, and 650°C) and atmospheres (ammonia and nitrogen) for 4 h. The fibers had diameters of 50 to 200 nm and mainly featured anatase and rutile phases. The anatase phase decreased and the rutile phase increased with increasing temperature. Different nitrogen conditions exerted minimal effects on the TiO2 crystalline phase. Different nitriding atmospheres during preservation heating yielded various effects on fibers. The effect of nitrogen in ammonia atmosphere is better than that in nitrogen atmosphere. The fibers heat-treated at 600°C and subjected to preservation heating in NH3 showed high photocatalytic activity.

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Section: Resultsmentioning

confidence: 99%

The effects of atmosphere and calcined temperature on photocatalytic activity of TiO2 nanofibers prepared by electrospinning

Fang

Tang

et al. 2013

Nanoscale Res Lett

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“…The product yield was 93% at optimized conditions and it had a TOF of 7.85 min −1 [22]. Although our group used an approach almost like the approach of Obuya and her team, the percentage conversion obtained for the coupling of ArBr-STY in this paper was slightly lower (93% versus 89.7%).…”

Section: Metal Leaching and The Nature Of Catalysismentioning

confidence: 78%

“…This could be attributed to the fact that polar protic solvents are favourable for SN1 substitution reactions and hence will consume the strong bases in a side reaction. On the other hand, polar aprotic solvents are favourable for SN2 substitution reactions, believed to be taking place in the proposed mechanism hence higher product yields [22].…”

Section: Effect Of Basementioning

confidence: 92%

“…The difference between the surface area obtained by Obuya and her group and what is reported here could have resulted from local improvisations made on the electrospinning apparatus, lack of a pump, and use of glass Pasteur pipettes. Another reason could have been because of Pd NP preparation method and average molecular weight of the polymer [22].…”

Section: Bet Analysismentioning

confidence: 99%

“…Metal oxides have become the most lucrative Pd supports for heterogeneous catalysis due to their availability, low production costs, and photoinduced electron hole pairs on the surfaces of metal oxide which can be harvested to enhance electron transfer and their chemical reactivity [22,23]. The first paper on heterogenous Heck catalysis of Pd supported on an inorganic support was reported in 1990 [19,21], reporting the coupling of chlorobenzene and styrene in the presence of Pd/MgO, methanol solvent, and sodium carbonate as a base at 150 ∘ C. Several other reports have since been made and Table 1 summarizes the literature on metal oxide support and Heck reaction. Titania, a semiconductor, has attracted more research interest due to its large band gap ∼3.0-3.2 eV.…”

Section: Introductionmentioning

confidence: 99%

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Preparation and Characterization of Pd Modified TiO₂ Nanofiber Catalyst for Carbon–Carbon Coupling Heck Reaction

Nyangasi

Andala

Onindo

et al. 2017

Journal of Nanomaterials

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TiO 2 fibers were prepared through electrospinning of poly methyl methacrylate (PMMA) and titanium isopropoxide (TIP) solution followed by calcination of fibers in air at 500 ∘ C. Cetyltrimethylammonium bromide (CTAB) protected palladium nanoparticles (Pd NPs) prepared through reduction method were successfully adsorbed on the TiO 2 nanofibers (NF). Combined studies of X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) indicated that the synthesized Pd/TiO 2 had anatase. BET indicated that the synthesized TiO 2 and Pd/TiO 2 had a surface area of 53.4 and 43.4 m 2 /g, respectively. The activity and selectivity of 1 mol% Pd/TiO 2 in the Heck reaction have been investigated towards the Mizoroki-Heck carbon-carbon cross-coupling of bromobenzene (ArBr) and styrene. Temperature, time, solvent, and base were optimized and catalyst was recycled thrice.1 H NMR and 13 C NMR indicated that stilbene, a known compound from literature, was obtained in various Heck reactions at temperatures between 100 ∘ C and 140 ∘ C but the recyclability was limited due to some palladium leaching and catalyst poisoning which probably arose from some residual carbon from the polymer. The catalyst was found to be highly active under air atmosphere with reaction temperatures up to 140 ∘ C. Optimized reaction condition resulted in 89.7% conversions with a TON of 1993.4 and TOF value of 332.2 hr −1 .

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Catalytic oxidation of thioanisole using oxovanadium(IV)‐functionalized electrospun polybenzimidazole nanofibers

Walmsley

Hlangothi

Litwinski

et al. 2012

J of Applied Polymer Sci

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Polybenzimidazole fibers, with an average diameter of 262 nm, were produced by the process of electrospinning. These fibers were used as a solid support material for the immobilization of oxovanadium(IV) which was achieved via a reaction with vanadyl sulfate. The oxovanadium(IV)-functionalized nanofibers were used as heterogeneous catalysts for the oxidation of thioanisole under both batch and pseudo-continuous flow conditions with great success. Under batch conditions near quantitative oxidation of thioanisole was achieved in under 90 min, even after four successive catalytic reactions. Under continuous conditions, excellent conversion of thioanisole was maintained throughout the period studied at flow rates of up to 2 mLh À1 . This study, therefore, proposes that electrospun polybenzimidazole nanofibers, with their small diameters, impressive chemical and thermal stability, as well as coordinating benzimidazole group, may be a desirable support material for immobilization of homogeneous catalysts.

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Photodeposited Pd nanoparticle catalysts supported on photoactivated TiO2 nanofibers

Cited by 34 publications

References 32 publications

The effects of atmosphere and calcined temperature on photocatalytic activity of TiO2 nanofibers prepared by electrospinning

The effects of atmosphere and calcined temperature on photocatalytic activity of TiO2 nanofibers prepared by electrospinning

Preparation and Characterization of Pd Modified TiO₂ Nanofiber Catalyst for Carbon–Carbon Coupling Heck Reaction

Catalytic oxidation of thioanisole using oxovanadium(IV)‐functionalized electrospun polybenzimidazole nanofibers

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Photodeposited Pd nanoparticle catalysts supported on photoactivated TiO2 nanofibers

Cited by 34 publications

References 32 publications

The effects of atmosphere and calcined temperature on photocatalytic activity of TiO2 nanofibers prepared by electrospinning

The effects of atmosphere and calcined temperature on photocatalytic activity of TiO2 nanofibers prepared by electrospinning

Preparation and Characterization of Pd Modified TiO2 Nanofiber Catalyst for Carbon–Carbon Coupling Heck Reaction

Catalytic oxidation of thioanisole using oxovanadium(IV)‐functionalized electrospun polybenzimidazole nanofibers

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Preparation and Characterization of Pd Modified TiO₂ Nanofiber Catalyst for Carbon–Carbon Coupling Heck Reaction