Characterization of Catalytic Supports by Infrared Spectroscopy and ESCA

1982 ◽  
Vol 36 (4) ◽  
pp. 361-368 ◽  
Author(s):  
Larry F. Wieserman ◽  
David M. Hercules
Keyword(s):  
Infrared Spectroscopy ◽  
Surface Area ◽  
Elevated Temperatures ◽  
Silica Alumina ◽  
Free Hydroxyl ◽  
Ft Ir ◽  
Catalytic Supports ◽  
Silica And Titania

This study compares the properties of γ-alumina, silica, and titania using ESCA and in situ FT-IR. The FWHM's of the O1s and metal 2p ESCA peaks increased systematically from titania to γ alumina; the O1s/metal 2p ESCA peak area ratios were nearly equal for γ-alumina and silica. For titania, however, the value was half that obtained for γ-alumina. In situ FT-IR showed hydroxyl bands with increasing frequencies from titania to silica. Alumina and titania form carbonate-type structures after exposure to CO at elevated temperatures. Silica exhibited no additional bands after CO treatment that could be assigned to physically adsorbed CO or carbonate-type structures. At 100°C, there is a direct correlation between the specific surface area and the intensity of infrared absorbance of the free-hydroxyl and the hydrogen-bonded hydroxyl bands for silica. The intensities of the infrared bands due to matrix modes were not affected by surface area.

Diffuse Reflectance FT-IR Characterization of Active Sites under Reaction Conditions: The Production of Oxygenates in the CO/H2 Reaction

1994 ◽  
Vol 48 (10) ◽  
pp. 1208-1212 ◽  
Author(s):  
J. J. Benítez ◽  
I. Carrizosa ◽  
J. A. Odriozola
Keyword(s):  
Infrared Spectra ◽  
Active Sites ◽  
Diffuse Reflectance ◽  
Reaction Conditions ◽  
In Situ Drifts ◽  
Ft Ir

The reactivity of a Lu2O3-promoted Rh/Al2O3 catalyst in the CO/H2 reaction is reported. Methane, heavier hydrocarbons, methanol, and ethanol are obtained. In situ DRIFTS has been employed to record the infrared spectra under the actual reaction conditions. The structure of the observed COads DRIFTS bands has been resolved into its components. The production of oxygenates (methanol and ethanol) has been correlated with the results of the deconvolution calculation. Specific sites for the production of methanol and ethanol in the CO/H2 reaction over a Rh,Lu2O3/Al2O3 catalyst are proposed.

In-Situ Characterization of Growth and Intermixing at a Heteroepitaxial Interface: Fe on Au(001)

1993 ◽  
Vol 318 ◽  
Author(s):  
Q. Jiang ◽  
A. Chan ◽  
Y.-L. He ◽  
G.-C. Wang
Keyword(s):  
Elevated Temperatures ◽  
Chemical Elements ◽  
Background Intensity ◽  
In Situ Characterization ◽  
Initial Stage ◽  
Monolayer Growth ◽  
Low Energy Electron ◽  
Energy Dependent

ABSTRACTThe growth and chemical intermixing of submonolayer and a few monolayer thick Fe films on a Au(001) surface was studied by High Resolution Low Energy Electron Diffraction (HRLEED) technique. Through the analysis of the energy dependent angular profiles as a function of time, we obtained the distribution of islands and distribution of spacings during submonolayer growth. The interference of electron waves from different chemical elements in terraces at different heights in the surface contributes to the background intensity and broadening in the angular profiles of diffraction beams. A subsurface Fe capped by Au islands as a result of atomic place exchange was observed at the initial stage of monolayer growth. From the energy dependent angular profiles as a function of temperature, we determine the quantitative change of inhomogeneity length (∼20 Å) at the interface of ultrathin films at elevated temperatures due to intermixing.

scholarly journals Characterization of the Physical, Chemical, and Adsorption Properties of Coal-Fly-Ash–Hydroxyapatite Composites

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 774
Author(s):  
Eleonora Sočo ◽  
Dorota Papciak ◽  
Magdalena M. Michel ◽  
Dariusz Pająk ◽  
Andżelika Domoń ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Synthesis Conditions ◽  
High Calcium ◽  
Ft Ir ◽  
Ir Analysis ◽  
Wet Synthesis

(1) Hydroxyapatite (Hap), which can be obtained by several methods, is known to be a good adsorbent. Coal fly ash (CFA) is a commonly reused byproduct also used in environmental applications as an adsorbent. We sought to answer the following question: Can CFA be included in the method of Hap wet synthesis to produce a composite capable of adsorbing both heavy metals and dyes? (2) High calcium lignite CFA from the thermal power plant in Bełchatów (Poland) was used as the base to prepare CFA–Hap composites. Four types designated CFA–Hap1–4 were synthesized via the wet method of in situ precipitation. The synthesis conditions differed in terms of the calcium reactants used, pH, and temperature. We also investigated the equilibrium adsorption of Cu(II) and rhodamine B (RB) on CFA–Hap1–4. The data were fitted using the Langmuir, Freundlich, and Redlich–Peterson models and validated using R2 and χ2/DoF. Surface changes in CFA–Hap2 following Cu(II) and RB adsorption were assessed using SEM, SE, and FT-IR analysis. (3) The obtained composites contained hydroxyapatite (Ca/P 1.67) and aluminosilicates. The mode of Cu(II) and RB adsorption could be explained by the Redlich–Peterson model. The CFA–Hap2 obtained using CFA, Ca(NO3)2, and (NH4)2HPO4 at RT and pH 11 exhibited the highest maximal adsorption capacity: 73.6 mg Cu/g and 87.0 mg RB/g. (4) The clear advantage of chemisorption over physisorption was indicated by the Cu(II)–CFA–Hap system. The RB molecules present in the form of uncharged lactone were favorably adsorbed even on strongly deprotonated CFA–Hap surfaces.

scholarly journals Hydrogenative Cyclization of Levulinic Acid to γ-Valerolactone with Methanol and Ni-Fe Bimetallic Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1096
Author(s):  
Ligang Luo ◽  
Xiao Han ◽  
Qin Zeng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Levulinic Acid ◽  
Hydrogen Donor ◽  
Effect Of Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Temperature Programmed

A series of Ni-Fe/SBA-15 catalysts was prepared and tested for the catalytic hydrogenation of levulinic acid to γ-valerolactone, adopting methanol as the only hydrogen donor, and investigating the synergism between Fe and Ni, both supported on SBA-15, towards this reaction. The characterization of the synthesized catalysts was carried out by XRD (X-ray powder diffraction), TEM (transmission electron microscopy), H2-TPD (hydrogen temperature-programmed desorption), XPS (X-ray photoelectron spectroscopy), and in situ FT-IR (Fourier transform–infrared spectroscopy) techniques. H2-TPD and XPS results have shown that electron transfer occurs from Fe to Ni, which is helpful both for the activation of the C=O bond and for the dissociative activation of H2 molecules, also in agreement with the results of the in situ FT-IR spectroscopy. The effect of temperature and reaction time on γ-valerolactone production was also investigated, identifying the best reaction conditions at 200 °C and 180 min, allowing for the complete conversion of levulinic acid and the complete selectivity to γ-valerolactone. Moreover, methanol was identified as an efficient hydrogen donor, if used in combination with the Ni-Fe/SBA-15 catalyst. The obtained results are promising, especially if compared with those obtained with the traditional and more expensive molecular hydrogen and noble-based catalysts.

scholarly journals Revealing electrolyte oxidation via carbonate dehydrogenation on Ni-based oxides in Li-ion batteries by in situ Fourier transform infrared spectroscopy

2020 ◽  
Vol 13 (1) ◽  
pp. 183-199 ◽  
Author(s):  
Yirui Zhang ◽  
Yu Katayama ◽  
Ryoichi Tatara ◽  
Livia Giordano ◽  
Yang Yu ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Li Ion Batteries ◽  
Ft Ir ◽  
Li Ion ◽  
Electrolyte Oxidation

Carbonate oxidation via dehydrogenation on LiNi0.8Co0.1Mn0.1O2 at voltages as low as 3.8 VLi was revealed by in situ FT-IR measurements.

Study on the Synthesis and Characterization of PANi/Nano-CeO2 Composites

2007 ◽  
Vol 124-126 ◽  
pp. 287-290 ◽  
Author(s):  
Fei Liu ◽  
Yong Jun He ◽  
Jeung Soo Huh
Keyword(s):  
In Situ Polymerization ◽  
Solid Phase ◽  
Polymerization Reaction ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Average Size

The nano-CeO2 was synthesized by two-step solid-phase reaction. The image of TEM showed that nano-CeO2 with an average size of about 70 nm. The series of polyaniline/nano-CeO2 composites with different PANi: CeO2 ratios were prepared by in-situ polymerization in the presence of hydrochloric acid (HCl) as dopant by adding nano-CeO2 into the polymerization reaction mixture of aniline. The composites obtained were characterized by FT-IR and UV-vis spectroscopy analysis. The FT-IR spectra of nanocomposites indicate different blue-shifts, attributed to C–N stretching mode for benzenoid unit. The UV-vis spectra of nanocomposites display einstein-shifts compared with PANi at 620nm. The conductivity properties of the composites are also changed compare to the pure PANi. These results suggest that the interactions between the polymer matrix and nanoparticles take place in polyaniline/nano- CeO2 composites.

The Preparation and Characterization of the Solid Acid Catalyst for the Esterification of the Gutter Oil

2014 ◽  
Vol 881-883 ◽  
pp. 297-301 ◽  
Author(s):  
Yan Zhi Liu ◽  
Shun Ping Wang ◽  
Kun Yuan ◽  
Huian Tang
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Active Carbon ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Raw Material ◽  
Ft Ir

The solid acid catalyst (ACSA) for the gutter oil esterification to biodiesel was prepared via active carbon as raw material by introducing the-SO3H group onto the surface of it. The ACSA were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and elemental analysis (EA), respectively. And the results showed that the-SO3H groups were successfully introduced onto the surface of the active carbon and the containing of the-SO3H groups are higher than 0.017g per gram of ACSA.

scholarly journals Incorporation of silver (I) ions within zeolite cavities and their photocatalytic reactivity for the decomposition ofN2OintoN2andO2

2003 ◽  
Vol 5 (1) ◽  
pp. 17-19 ◽  
Author(s):  
Woo-Sung Ju ◽  
Masaya Matsuoka ◽  
Masakazu Anpo
Keyword(s):  
Ion Exchange ◽  
Uv Light ◽  
Photocatalytic Decomposition ◽  
Effective Wavelength ◽  
In Situ Characterization ◽  
Exchange Method ◽  
Ft Ir ◽  
Ion Exchange Method

Ag+/ZSM-5 catalysts were prepared by an ion-exchange method. UV-irradiation of theAg+/ZSM-5 catalysts in the presence ofN2Oled to the photocatalytic decomposition ofN2OintoN2andO2at 298 K. Investigations of the effective wavelength of the irradiated UV-light for the reaction as well as the in-situ characterization of the catalysts by means of UV-Vis, photoluminescence and FT-IR spectroscopies revealed that the photoexcitation of theAg+−N2Ocomplexes formed between gaseousN2Oand the isolatedAg+ions exchanged within the zeolite cavities plays a significant role in the reaction.

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