In situ FT-IR studies on mechanistics of heterogeneous photocatalytic oxidation of ethene over uranyl species anchored on MCM-41

Poly(3-octylthiophene) (P3OT)-titanium dioxide (TiO2) nanocomposite powder where TiO2 was embedded with homogeneous dispersion was synthesized by in-situ chemical oxidative polymerization of 3-octylthiophene in the presence of TiO2 nanoparticles in supercritical carbon dioxide (scCO2), using ferric chloride as the oxidant. The synthesized materials could be obtained as dry powder upon venting of CO2 after the polymerization. The composites were subsequently characterized by FT-IR spectroscopy, transmission electron microscopy (TEM), X-ray diffraction studies (XRD), thermogravimetric analysis (TGA) and photoluminescence (PL). The incorporation of TiO2 in the composite was endorsed by FT-IR studies. TGA revealed enhanced thermal stability of P3OT/TiO2 nanocomposite compared to 3-octylthiophene. TEM analysis showed that well dispersed TiO2 nanoparticles in the polymer matrix. Photoluminescence quenching increased with increasing TiO2 concentration in the composite.

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In Situ FT-IR Studies on the Amine-Catalyzed Urethane Reaction Kinetics of 1,3-Butanediol

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.472-475.2223 ◽

2012 ◽

Vol 472-475 ◽

pp. 2223-2226

Author(s):

Peng Fei Yang

Keyword(s):

Rate Constant ◽

Phenyl Isocyanate ◽

Hydroxyl Group ◽

Activation Entropy ◽

Ir Studies ◽

Initial Stage ◽

Different Temperatures ◽

Ft Ir ◽

Kinetics Of

Phenyl isocyanate is used to react with 1,3-butanediol at different temperatures. Toluene is used as solvent and 1,4-diazabicyclo[2,2,2]octane is used as catalyst. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of primary hydroxyl group are calculated out, which are 26.4 kJ•mol-1, 23.6 kJ•mol-1and -186.6 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.

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In Situ FT-IR Studies of the Zirconium (IV) Acetylacetonate Catalyzed Urethane Reaction of Butanediols

International Journal of Polymer Analysis and Characterization ◽

10.1080/1023666x.2013.747426 ◽

2013 ◽

Vol 18 (2) ◽

pp. 119-125 ◽

Cited By ~ 1

Author(s):

Shun Ping Wang ◽

Xiao Deng Yang ◽

Qing Quan Bai ◽

Tian Duo Li

Keyword(s):

Ir Studies ◽

Ft Ir

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In Situ FT-IR Study of Rh−Al−MCM-41 Catalyst for the Selective Catalytic Reduction of Nitric Oxide with Propylene in the Presence of Excess Oxygen

The Journal of Physical Chemistry B ◽

10.1021/jp984525d ◽

1999 ◽

Vol 103 (12) ◽

pp. 2232-2238 ◽

Cited By ~ 31

Author(s):

R. Q. Long ◽

R. T. Yang

Keyword(s):

Nitric Oxide ◽

Selective Catalytic Reduction ◽

Catalytic Reduction ◽

Excess Oxygen ◽

Ft Ir ◽

Ir Study ◽

Mcm 41

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The Temperature-Dependent Adsorption Behaviour of Benzene Molecules in ZSM-5 Zeolite Pores: TPD and FT-IR Spectroscopy Studies

Adsorption Science & Technology ◽

10.1260/0263617054037808 ◽

2005 ◽

Vol 23 (2) ◽

pp. 95-107 ◽

Cited By ~ 1

Author(s):

Arati Sahasrabudhe ◽

Salil Varma ◽

Narendra M. Gupta

Keyword(s):

Benzene Molecule ◽

Hydroxyl Groups ◽

Fixed Amount ◽

Oh Groups ◽

Ir Studies ◽

Ft Ir ◽

Temperature Programmed ◽

Spectroscopy Studies ◽

Ir Spectroscopic

Temperature-programmed desorption (TPD) and in situ Fourier-transform infrared (FT-IR) spectroscopic methods were employed to investigate the effect of loading and sample temperature on the state of benzene molecules inside the channels of NaZSM-5 zeolite. TPD profiles revealed the existence of at least three distinct states of benzene adsorption, characterized by desorption peak maxima at ca. 120°C, 170°C and 220°C, respectively. Based on the growth behaviour of these bands, it is suggested that the benzene molecules occupy sinusoidal channels, straight channels and external surfaces, in that order. A reverse trend was observed during the subsequent flushing of the sample at varying temperatures. A virtually fixed amount of benzene was occluded at these three locations, depending upon the loading. The FT-IR studies revealed that the benzene molecule exists in a compressed state in the zeolitic channels, with the molecular clusters formed in the process dispersing only at temperatures above 150°C. For initial benzene loadings of up to ca. 1.5 molecules/unit cell, the spectrum obtained showed that in the O—H stretch region the bridge-bonded OH groups and hydroxyl groups associated with the internal zeolitic channels were perturbed simultaneously. The results show that even for a loading lower than necessary for saturation, a considerable amount of benzene remains condensed at the external surface of ZSM-5 zeolite.

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In Situ FT-IR Studies of Oxide and Oxynitride Sol-Gel-Derived Thin Films

MRS Proceedings ◽

10.1557/proc-32-267 ◽

1984 ◽

Vol 32 ◽

Cited By ~ 9

Author(s):

David M. Haaland ◽

C. Jeffrey Brinker

Keyword(s):

Thin Film ◽

Thin Films ◽

High Temperature ◽

Low Temperatures ◽

Sol Gel ◽

Ir Studies ◽

Oxynitride Glass ◽

Vibrational Bands ◽

Ft Ir

ABSTRACTA high-temperature infrared cell was developed to study the gel-to-glass conversion of sol-gel-derived thin films. FT-IR spectra of matched thin-film borosilicate sol-gel samples were taken as the samples were heated at 100°C intervals to 700°C in either air or ammonia. The gels were converted to oxide and oxynitride glasses, respectively, by these heat treatments. The gel-to-glass conversion could be followed and compared for these two treatments by monitoring changes in the vibrational bands present in the spectra. Comparisons between the infrared spectra of NH3-treated and air-treated films heated above 500°C reveal the appearance of new B-N bonds at the expense of B-O-Si bonds for the NH3-fired films. These spectra also exhibit changes which may indicate the formation of Si-N bonds. Thus, ammonolysis reactions can result in thin-film oxynitride glass formation at relatively low temperatures.

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