FT-IR studies of the interaction between zeolitic hydroxyl groups and small molecules. 1. Adsorption of nitrogen on H-mordenite at low temperature

1993 ◽  
Vol 97 (41) ◽  
pp. 10761-10768 ◽  
Author(s):  
Fumitaka Wakabayashi ◽  
Junko Kondo ◽  
Akihide Wada ◽  
Kazunari Domen ◽  
Chiaki Hirose
Keyword(s):  
Low Temperature ◽  
Small Molecules ◽  
Hydroxyl Groups ◽  
Ir Studies ◽  
Adsorption Of Nitrogen ◽  
Ft Ir

FT-IR Studies of Interaction between Zeolitic Hydroxyl Groups and Small Molecules. 2. Adsorption of Oxygen, Hydrogen, and Rare Gases on H-Mordenite at Low Temperatures

1995 ◽  
Vol 99 (40) ◽  
pp. 14805-14812 ◽  
Author(s):  
Fumitaka Wakabayashi ◽  
Tatsuya Fujino ◽  
Junko N. Kondo ◽  
Kazunari Domen ◽  
Chiaki Hirose
Keyword(s):  
Small Molecules ◽  
Low Temperatures ◽  
Hydroxyl Groups ◽  
Rare Gases ◽  
Ir Studies ◽  
Ft Ir

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

2005 ◽  
Vol 23 (2) ◽  
pp. 95-107 ◽  
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.

Low temperature FT-IR studies of NO adsorption on aluminum oxide and supported palladium

2001 ◽  
Vol 167 (1-2) ◽  
pp. 67-79 ◽  
Author(s):  
Dilip K. Paul ◽  
Barry W. Smith ◽  
Chad D. Marten ◽  
Justin Burchett
Keyword(s):  
Low Temperature ◽  
Aluminum Oxide ◽  
No Adsorption ◽  
Ir Studies ◽  
Ft Ir ◽  
Supported Palladium

scholarly journals Synthesis, Fabrication, and Characterization of Functionalized Polydiacetylene Containing Cellulose Nanofibrous Composites for Colorimetric Sensing of Organophosphate Compounds

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1869
Author(s):  
A K M Mashud Alam ◽  
Donovan Jenks ◽  
George A. Kraus ◽  
Chunhui Xiang
Keyword(s):  
Solid State ◽  
Hydroxyl Groups ◽  
Colorimetric Sensing ◽  
Electrospinning Technique ◽  
Hazardous Chemical ◽  
Tensile Tester ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Landmark Study

Organophosphate (OP) compounds, a family of highly hazardous chemical compounds included in nerve agents and pesticides, have been linked to more than 250,000 annual deaths connected to various chronic diseases. However, a solid-state sensing system that is able to be integrated into a clothing system is rare in the literature. This study aims to develop a nanofiber-based solid-state polymeric material as a soft sensor to detect OP compounds present in the environment. Esters of polydiacetylene were synthesized and incorporated into a cellulose acetate nanocomposite fibrous assembly developed with an electrospinning technique, which was then hydrolyzed to generate more hydroxyl groups for OP binding. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Instron® tensile tester, contact angle analyzer, and UV–Vis spectroscopy were employed for characterizations. Upon hydrolysis, polydiacetylene esters in the cellulosic fiber matrix were found unaffected by hydrolysis treatment, which made the composites suitable for OP sensing. Furthermore, the nanofibrous (NF) composites exhibited tensile properties suitable to be used as a textile material. Finally, the NF composites exhibited colorimetric sensing of OP, which is visible to the naked eye. This research is a landmark study toward the development of OP sensing in a protective clothing system.

scholarly journals Characterization and Catalytic Behaviour of Co3(PO4)2–AlPO4 Catalysts

1998 ◽  
Vol 16 (4) ◽  
pp. 285-293 ◽  
Author(s):  
M.R. Mostafa ◽  
F.Sh. Ahmed
Keyword(s):  
Pore Radius ◽  
Surface Acidity ◽  
Total Pore Volume ◽  
Textural Properties ◽  
Acid Sites ◽  
Adsorption Of Nitrogen ◽  
Amorphous Structures ◽  
Ft Ir ◽  
Catalytic Behaviour ◽  
The Mean

Co3(PO4)2, AlPO4 and the binary system Co3(PO4)2-AlPO4 with different compositions were prepared by the coprecipitation method. The structural properties of these samples were determined using XRD, DTA and FT-IR techniques. The textural properties were determined from the adsorption of nitrogen at 77 K. The surface acidity was measured by a calorimetric titration method. The samples were tested as catalysts in the dehydration of ethanol and isopropanol using a pulse microcatalytic technique. The data obtained from XRD and FT-IR indicate the amorphous structures of the prepared catalysts. An increase in Co3(PO4)2 content led to a decrease in the surface area and in the total pore volume and an increase in the mean pore radius. The surface acidity of the catalyst depends on the chemical composition; the surface acidity increased with an increase in the AlPO4 content. The dehydration temperature and the distribution of acid sites are important parameters in determining the selectivity and activity of the catalyst.

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