Swellable Organically Modified Silica (SOMS) as a Catalyst Scaffold for Catalytic Treatment of Water Contaminated with Trichloroethylene

Çelik, Gökhan
Sohn, Hyuntae
Tang, Yu
Tao, Franklin Feng
Miller, Jeffrey T.
Edmiston, Paul L.
Ozkan, Umit S.
The properties of a swellable organically modified silica (SOMS) scaffold allowed us to synthesize "smart" catalysts with tunable accessibility of the active sites induced by organic swelling agents. Pd nanoparticles (NPs) deposited inside the swollen matrix of SOMS were shown to be selectively located on the interior surface, a surface which is only available through swelling. Techniques such as near ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) and cryogenic scanning electron microscopy (SEM) were employed to characterize Pd/SOMS in its swollen as well as unswollen state because their conventional counterparts do not preserve the swollen state of Pd/SOMS during spectral acquisition. The results obtained depicted significant differences between the unswollen and swollen state of Pd/SOMS. The most important difference is that Pd NPs became accessible on the surface after exposure to an organic compound. This indicates that the accessibility of the active sites can be controlled by changing the reaction environment, hence allowing a tunable accessibility induced by organic swelling agents. The effects of the extent of swelling on the catalytic activity were investigated by performing catalytic activity experiments in the presence of an organic swelling agent. Hydrodechlorination (HDC) of trichloroethylene (TCE), an important method of catalytic water abatement, was chosen as a model reaction. The catalytic performance was found to be proportional to the concentration of the organic swelling agent, indicating that the accessibility of active sites is related to the concentration of organic compounds. While the unavoidable reaction product HCl inhibited the commonly used HDC catalyst 1%Pd/Al2O3, 1%Pd/SOMS was able to maintain its rate throughout the reaction under the same conditions, indicating its resistance to the inhibition. Overall, a silica-based catalyst with tunable accessibility of the active sites induced by changes in the reaction environment can have significant implications for heterogeneous catalysis.
ACS Catalysis


Swellable Organically Modified Silica (SOMS): A Novel Support for Aqueous Phase Hydrodechlorination of Trichloroethylene
Ailawar, Saurabh A.; Çelik, Gökhan; Hunoor, Anagha; Gunduz, Seval; Edmiston, Paul L.; Ozkan, Umit S. (2019-06-28)
This study focuses on the use of swellable organically modified silica (SOMS) as a catalyst support for aqueous-phase hydrodechlorination of trichloroethylene. SOMS is extremely hydrophobic and swells volumetrically when contacted with organics. These properties should help overcome the disadvantages associated with the commercial catalyst (Pd/Al2O3), such as deactivation by anions.
ZHU, J; Karakaya, İshak; THOMPSON, WT (The Electrochemical Society, 1988-01-01)
To further the understanding of electrolytes of value in industrial magnesium electrolysis, the reversible emf for the formation of in fused salts containing and was studied. The data made possible the calculation of thermodynamic solution properties which were used with other data to construct features of the ternary phase diagram. The multiple discrete complex anion (MDCA) model was tested against the thermodynamic findings from the present study. Reasonable agreement was obtained between the experimen...
Effect of high-temperature on the swellable organically-modified silica (SOMS) and its application to gas-phase hydrodechlorination of trichloroethylene
Sohn, Hyuntae; Çelik, Gökhan; Gunduz, Seval; Majumdar, Sreshtha Sinha; Dean, Stacey L.; Edmiston, Paul L.; Ozkan, Umit S. (2017-01-01)
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 tr...
Processable and multichromic polymer of bis-3-hexylthiophene substituted 4-tert-butylphenyl quinoxaline
Ozyurt, Funda; Günbaş, Emrullah Görkem; Durmus, Asuman; Toppare, Levent Kamil (Elsevier BV, 2008-06-01)
A new polythiophene derivative, poly-2,3-bis(4-tert-butylphenyl)-5,8-bis(4-hexylthiophen-2-yl)quinoxaline (PHTQ) was synthesized by both chemical and electrochemical polymerization and its electrochemical properties were reported. The monomer was electrochemically polymerized in the presence of tetrabutylammonium hexafluoropbosphate (TBAPF(6)) as the supporting electrolyte in dichloromethane-acetonitrile (5:95, v:v). Nuclear magnetic resonance (H-1 NMR) and Fourier transform infrared (FTIR) were utilized fo...
Electrochemical preparation and characterization of carbon fiber reinforced poly (dimethyl siloxane)/polythiophene composites: electrical, thermal and mechanical properties
Sankir, M; Kucukyavuz, S; Kucukyavuz, Z (Elsevier BV, 2002-05-10)
A series of polydimethylsiloxane (PDMS)/polythiophene (Pth)/carbon fiber (CF) composites was synthesized by electrochemical polymerization using tetrabutylammoniumtetrafluoroborate (TBAFB) as supporting electrolyte and acetonitrile as solvent. Composites were characterized by TGA, SEM, and mechanical tests and conductivity measurements. Conductivities of composites were in the range of 25 S/cm. SEM studies show that CF were coated by PDMS/Pth matrix and well oriented in the matrix. In mechanical tests it ha...
Citation Formats
G. Çelik et al., “Swellable Organically Modified Silica (SOMS) as a Catalyst Scaffold for Catalytic Treatment of Water Contaminated with Trichloroethylene,” ACS Catalysis, pp. 6796–6809, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35039.