Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Effect of high-temperature on the swellable organically-modified silica (SOMS) and its application to gas-phase hydrodechlorination of trichloroethylene
Date
2017-01-01
Author
Sohn, Hyuntae
Çelik, Gökhan
Gunduz, Seval
Majumdar, Sreshtha Sinha
Dean, Stacey L.
Edmiston, Paul L.
Ozkan, Umit S.
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
204
views
0
downloads
Cite This
Pd catalysts supported on swellable organically-modified silica (SOMS) and high-temperature treated swellable organically-modified silica (H-SOMS) were characterized and tested for gas-phase hydrodechlorination (HDC) of trichloroethylene (TCE) conditions. The high-temperature treatment on SOMS resulted in an increase in surface area and pore diameter as well as significant improvement of Pd dispersion on H-SOMS with smaller Pd particle sizes compared to the Pd/SOMS catalyst. Although the high-temperature treatment led to some alteration of the SOMS polysiloxane network, the hydrophobicity and organic vapor adsorption characteristics of SOMS were preserved. The reduction and oxidation characteristics of Pd on SOMS and HSOMS were investigated in situ using XANES technique. It was found that the Pd sites in the pores of SOMS was accessible to small molecules such as H-2, facilitating the reduction of PdOx, whereas oxidation of metallic Pd was limited even at higher temperatures when O-2 was used. This effect was only observed over Pd/SOMS catalyst. For Pd/H-SOMS, because the pores were more widely open than Pd/SOMS, both reduction and oxidation of Pd were observed. Finally, the catalytic activity of Pd/H-SOMS for gas-phase HDC of TCE was significantly better than Pd/SOMS. When water was added to the reactant stream (TCE + H2O), both Pd/SOMS and Pd/H-SOMS maintained its catalytic performances due to hydrophobic property of the supports.
Subject Keywords
Organically-modified silica (SOMS)
,
Trichloroethylene
,
Hydrodechlorination (HDC)
URI
https://hdl.handle.net/11511/37536
Journal
Applied Catalysis B: Environmental
DOI
https://doi.org/10.1016/j.apcatb.2017.02.056
Collections
Department of Chemical Engineering, Article
Suggestions
OpenMETU
Core
Hydrodechlorination of trichloroethylene over Pd supported on swellable organically-modified silica (SOMS)
Sohn, Hyuntae; Çelik, Gökhan; Gunduz, Seval; Dean, Stacey L.; Painting, Eric; Edmiston, Paul L.; Ozkan, Umit S. (2017-04-01)
The catalytic activity and resistance to poisoning of Pd catalysts supported on swellable organically modified silica (SOMS) were investigated for hydrodechlorination (HDC) of trichloroethylene (TCE). The promising catalytic activity of 1% Pd/SOMS sample was attributed to the high affinity of SOMS for organics and its high hydrophobicity. While latter characteristic repels water, the adsorptive capacity for organics allows TCE dissolved in aqueous media to concentrate inside the pores, in the vicinity of th...
Effect of process control agents on synthesizing nano-structured 2Mg-9Ni-Y catalyst by mechanical milling and its catalytic effect on desorption capacity of MgH2
Hosseini-Gourajoubi, Faranak; Pourabdoli, Mehdi; Üner, Deniz; Raygan, Shahram (2015-03-01)
Synthesizing 2Mg-9Ni-Y catalyst was investigated by mechanical alloying of Mg, Ni, and Y elemental powder mixture and subsequent heat treatment. Accordingly, effects of milling time, process control agent (PCA) type (stearic acid and toluene), and heat treatment time on the powder microstructure, phase composition, and powder morphology were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and laser particle size analyzer (LPSA). Results showed that particle size of the samples prepar...
On the dual role of the reactant during aqueous phase hydrodechlorination of trichloroethylene (HDC of TCE) using Pd supported on swellable organically modified silica (SOMS)
Ailawar, Saurabh; Hunoor, Anagha; Rudzinski, Benjamin; Çelik, Gökhan; Burel, Laurence; Millet, Jean-Marc; Miller, Jeffrey T.; Edmiston, Paul L.; Ozkan, Umit S. (2021-08-01)
Herein, the dual role of trichloroethylene (TCE) in liquid-phase hydrodechlorination with Pd catalysts supported on swellable organically modified silica (SOMS), is investigated. Batch experiments with TCE-soaked Pd/SOMS showed 45% higher conversion after 4 h than dry Pd/SOMS, suggesting that TCE acts as a reactant and as a swelling-agent. Flow experiments performed with and without ethanol (external swelling-agent) exhibited similar steady-state activities, confirming that TCE itself can cause swelling. Mo...
Effect of pectin methyl esterase (PME) and CaCl2 infusion on the cell integrity of fresh-cut and frozen-thawed mangoes: An NMR relaxometry study
Kırtıl, Emrah; Öztop, Halil Mecit; Barrett, Diane M.; McCarthy, Michael J. (Elsevier BV, 2014-12)
This study describes the use of Nuclear Magnetic Resonance (NMR) relaxometry to understand the effect of pectin methyl esterase (PME) + CaCl2 infusion under different conditions on cell integrity of fresh-cut and frozen-thawed mangoes. Infusion experiments were performed at: atmospheric pressure, vacuum conditions of 50 kPa and 10 kPa. For NMR relaxometry experiments T-2 (spin-spin relaxation time), T-1 (spin-lattice-relaxation times) and 2D T-1-T-2 experiments were performed. Results showed that, as the se...
Synthesis of new pyrazolium based tunable aryl alkyl ionic liquids and their use in removal of methylene blue from aqueous solution
Özdemir, Melek (2019-6-29)
In this study, two new pyrazolium based tunable aryl alkyl ionic liquids, 2-ethyl-1-(4-methylphenyl)-3,5- dimethylpyrazolium tetrafluoroborate (3a) and 1-(4-methylphenyl)-2-pentyl-3,5-dimethylpyrazolium tetrafluoroborate (3b), were synthesized via three-step reaction and characterized. The removal of methylene blue (MB) from aqueous solution has been investigated using the synthesized salts as an extractant and methylene chloride as a solvent. The obtained results show that MB was extracted from aqueous sol...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
H. Sohn et al., “Effect of high-temperature on the swellable organically-modified silica (SOMS) and its application to gas-phase hydrodechlorination of trichloroethylene,”
Applied Catalysis B: Environmental
, pp. 80–90, 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37536.