scholarly journals Определение коэффициента экстинкции моноксида углерода, адсорбированного на диоксиде титана

2021 ◽  
Vol 129 (11) ◽  
pp. 1400
Author(s):  
К.М. Буланин ◽  
А.Ю. Михелева ◽  
Д.Н. Щепкин ◽  
А.В. Рудакова
Keyword(s):  
Experimental Data ◽  
Carbon Monoxide ◽  
Infrared Spectroscopy ◽  
Extinction Coefficient ◽  
Room Temperature ◽  
Heterogeneous Systems ◽  
Tio2 Anatase ◽  
Weak Adsorption ◽  
Adsorption Of Co ◽  
Logarithmic Law

The adsorption of carbon monoxide on the TiO2 (anatase) surface at room temperature was studied by infrared spectroscopy and volumetry. The experimental data obtained indicate weak adsorption of CO molecules on the exponentially heterogeneous surface. The adsorption heat decreases according to the logarithmic law in the coverage range of 0.002-0.03. The extinction coefficient of adsorbed CO for the heterogeneous CO/TiO2 system is calculated using the Bouguer-Lambert-Beer law with correction for the Lorenz field taken into account. The conditions for the applicability of the Bouguer-Lambert-Beer's law for the study of heterogeneous systems are discussed.

scholarly journals FTIR study of carbon monoxide adsorption on ion-exchanged X, Y and mordenite type zeolites

2003 ◽  
Vol 68 (4-5) ◽  
pp. 409-416 ◽  
Author(s):  
Vesna Rakic ◽  
Vera Dondur ◽  
Radmila Hercigonja
Keyword(s):  
Carbon Monoxide ◽  
Fourier Transform ◽  
Transition Metal ◽  
Room Temperature ◽  
Ir Absorption ◽  
Transition Metal Cation ◽  
Absorption Bands ◽  
Ftir Study ◽  
Adsorption Of Co ◽  
Charge Balancing

In this work Fourier transform infrared (FTIR) study has been applied to study the adsorption of carbon monoxide on transition metal (Mn2+, Co2 Ni2+) ion-exchanged zeolites type Y, X and mordenites. The adsorption of CO at room temperature produces overlapping IR absorption bands in the 2120?2200 cm-1 region. The frequency of the band around 2200 cm-1 is found to be dependent not only on the charge-balancing transition metal cation but also on the framework composition. The frequencies of the band near 1600 cm-1 was found to be dependent on the Si/Al ratio of the investigated zeolites.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

A Series of Metal-Organic Frameworks for Selective CO2 Capture and Catalytic Oxidative Carboxylation of Olefins

2018 ◽  
Author(s):  
Huong T. D. Nguyen ◽  
Y B. N. Tran ◽  
Hung N. Nguyen ◽  
Tranh C. Nguyen ◽  
Felipe Gándara ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Adsorption ◽  
New Materials ◽  
One Pot ◽  
Acid Gas ◽  
Naphthalene Diimide ◽  
Styrene Carbonate ◽  
Metal Organic ◽  
Adsorption Of Co ◽  
The One

<p>Three novel lanthanide metal˗organic frameworks (Ln-MOFs), namely MOF-590, -591, and -592 were constructed from a naphthalene diimide tetracarboxylic acid. Gas adsorption measurements of MOF-591 and -592 revealed good adsorption of CO<sub>2</sub> (low pressure, at room temperature) and moderate CO<sub>2</sub> selectivity over N<sub>2</sub> and CH<sub>4</sub>. Accordingly, breakthrough measurements were performed on a representative MOF-592, in which the separation of CO<sub>2</sub> from binary mixture containing N<sub>2</sub> and CO<sub>2</sub> was demonstrated without any loss in performance over three consecutive cycles. Moreover, MOF-590, MOF-591, and MOF-592 exhibited catalytic activity in the one-pot synthesis of styrene carbonate from styrene and CO<sub>2</sub> under mild conditions (1 atm CO<sub>2</sub>, 80 °C, and solvent-free). Among the new materials, MOF-590 revealed a remarkable efficiency with exceptional conversion (96%), selectivity (95%), and yield (91%). </p><br>

scholarly journals Structure and Properties of Ln2MoO6 Oxymolybdates (Ln = La, Pr, Nd) Doped with Magnesium

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Ekaterina Orlova ◽  
Elena Kharitonova ◽  
Timofei Sorokin ◽  
Alexander Antipin ◽  
Nataliya Novikova ◽  
...  
Keyword(s):  
Rare Earth ◽  
Infrared Spectroscopy ◽  
Room Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Spectroscopy Data ◽  
Structure And Properties ◽  
Hygroscopic Properties ◽  
Thermogravimetric Studies ◽  
Mg Doped

The literature data and the results obtained by the authors on the study of the structure and properties of a series of polycrystalline and single-crystal samples of pure and Mg-doped oxymolybdates Ln2MoO6 (Ln = La, Pr, Nd) are analyzed. Presumably, the high-temperature phase I41/acd of Nd2MoO6 single crystals is retained at room temperature. The reason for the loss of the center of symmetry in the structures of La2MoO6 and Pr2MoO6 and the transition to the space group I4¯c2 is the displacement of oxygen atoms along the twofold diagonal axes. In all structures, Mg cations are localized near the positions of the Mo atoms, and the splitting of the positions of the atoms of rare-earth elements is found. Thermogravimetric studies, as well as infrared spectroscopy data for hydrated samples of Ln2MoO6 (Ln = La, Pr, Nd), pure and with an impurity of Mg, confirm their hygroscopic properties.

Carbon monoxide formation as an intermediate product in photocatalytic steam reforming of methane with lanthanum-doped sodium tantalate

2021 ◽  
Author(s):  
Wirya Sarwana ◽  
Akihiko Anzai ◽  
Daichi Takami ◽  
Akira Yamamoto ◽  
Hisao Yoshida
Keyword(s):  
Carbon Monoxide ◽  
Solar Energy ◽  
Steam Reforming ◽  
Intermediate Product ◽  
Room Temperature ◽  
Carbon Monoxide Formation ◽  
Steam Reforming Of Methane

Photocatalytic steam reforming of methane (PSRM) has been studied as an attractive method to produce hydrogen by utilizing photoenergy like solar energy around room temperature with metal-loaded photocatalysts, where methane...

scholarly journals Room-temperature carbon monoxide oxidation by oxygen over Pt/Al2O3 mediated by reactive platinum carbonates

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Mark A. Newton ◽  
Davide Ferri ◽  
Grigory Smolentsev ◽  
Valentina Marchionni ◽  
Maarten Nachtegaal
Keyword(s):  
Carbon Monoxide ◽  
Room Temperature ◽  
Carbon Monoxide Oxidation

Characterization and catalytic properties of a saponite clay modified by acid activation

Clay Minerals ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 633-643 ◽  
Author(s):  
F. Kooli ◽  
W. Jones
Keyword(s):  
Infrared Spectroscopy ◽  
Room Temperature ◽  
Textural Properties ◽  
Acid Sites ◽  
Single Type ◽  
Activation Process ◽  
Acid Activation ◽  
Strongly Correlated ◽  
Lewis Site ◽  
Adsorbed Pyridine

AbstractA natural saponite was acid activated at room temperature or 90°C with different acid/clay ratios and the products were characterized by powder X-ray diffraction, infrared spectroscopy and thermogravimetry. The leaching of Mg from the octahedral sheets is enhanced by an increase in the acid/clay ratio and by an increase in temperature of activation. Textural properties are reported, and it appears that they are strongly correlated to the presence of a noncrystalline silica phase which is formed during the acid activation process. The desorption of cyclohexylamine indicates that for samples activated at 90°C the number of acid sites in the acidactivated saponites decreases following severe acid treatment. Infrared spectroscopy of adsorbed pyridine on samples after calcination at 500°C suggests that acid activation at 90°C produces a single type of Bronsted site but two types of Lewis sites whereas activation at room temperature results in only one type of Lewis site in addition to a Brønsted site. The two Lewis sites are suggested to originate from residual Al in the clay structure and to AI exsolved from the layers during activation. The dehydration of pentan-1-ol has been used as a further probe to measure acidity by monitoring the degree of conversion and selectivity for the different samples.

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