Hydrodechlorination of trichloroethylene over Pd supported on swellable organically-modified silica (SOMS)

Date

2017-04-01

Author

Sohn, Hyuntae
Çelik, Gökhan
Gunduz, Seval
Dean, Stacey L.
Painting, Eric
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

66
views

0
downloads

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 the active sites, thus helping the kinetics. In the liquid phase, using a continuous flow reactor, higher TCE conversion was obtained over the 1% Pd/SOMS compared to the commercial 1% Pd/Al2O3 catalyst. When the pores of 1% Pd/SOMS sample were fully opened by pre-treating it with ethanol prior to the reaction, HDC activity was seen to significantly increase. In the gas phase, the extent of adsorption was less, reducing the concentration of reactants near the active sites. As a result, 1% Pd/SOMS was less active than 1% Pd/Al2O3 for HDC of TCE. To determine their resistance to poisoning, 1% Pd/SOMS and 1% Pd/A1203 catalysts were poisoned ex-situ with Li2S. The ex-situ poisoned Pd/SOMS sample maintained its catalytic activity for HDC of TCE. However, a significant loss in catalytic activity of the Pd/Al2O3 catalyst was observed after poisoning. Protection from aqueous phase sulfide poisoning was attributed to the hydrophobicity of the Pd/SOMS, which would exclude anionic species from the embedded Pd particles. The XPS, STEM and ICP-OES results indicated that when Pd/Al2O3 and Pd/SOMS were treated with 1 M HCI, most of the Pd metal was leached from the Pd/Al2O3 catalyst in contrast to Pd/SOMS, which had negligible leaching. Overall, due to hydrophobicity and high affinity for organics, SOMS has potential as a catalyst scaffold for different reactions in groundwater remediation applications.

Subject Keywords

SOMS, Palladium, Trichloroethylene, Hydrodechlorination, Organosilica

URI

https://hdl.handle.net/11511/37136

Journal

Applied Catalysis B: Environmental

DOI

https://doi.org/10.1016/j.apcatb.2016.10.032

Collections

Department of Chemical Engineering, Article

Suggestions

OpenMETU
Core

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...
Optical fluoride sensing with a bay region functionalized perylenediimide dye Yukruk, Funda (2006-01-01) A perylenedimiide (PDI) derivative functionalized at the perylene core (bay region) to carry phenyl boronic acid groups was shown to interact with fluoride with changes in the emission and absorption spectrum. These changes are most likely due to fluoride-induced aggregation and/or quenching of the perylenediimide dye. The dye is also selective; among halide ions, fluoride anions generate a significant response. Thus, this class of PDI derivatives is likely to be useful in practical fluoride sensing.
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...
Catalytic reaction of propylene to propylene oxide on various catalysts Kalyoncu, Şule; Önal, Işık; Şeker, Erol; Department of Chemical Engineering (2012) Throughout this thesis work, various catalysts were investigated with combinational approach to develop highly active and selective novel catalysts for direct epoxidation of propylene to PO using molecular oxygen. The promoted and un-promoted silver (Ag), copper (Cu), ruthenium (Ru), manganese (Mn) mono and multimetallic catalytic systems over different silica supports were prepared via sol-gel method and incipient wetness method. In addition to support effect, the effects of different promoters on the cata...
Hydrolytic dehydrogenation of ammonia borane catalyzed by reduced graphene oxide supported monodisperse palladium nanoparticles: High activity and detailed reaction kinetics Kilic, Buket; Sencanli, Selin; Metin, Onder (2012-09-01) A highly active and stable catalyst for the hydrolytic dehydrogenation of ammonia borane (AB) was prepared by supporting monodisperse palladium nanoparticles (Pd NPs) on reduced graphene oxide (RGO) via a facile method. RGO was prepared via modified chemical route and used as support matrices for monodisperse Pd NPs that were formed by the reduction of palladium(II) acetylacetonate by borane tert-butylamine complex in the presence of oleylamine. RGO supported Pd NPs (RGO@Pd) show high activity and stability...

Citation Formats

H. Sohn et al., “Hydrodechlorination of trichloroethylene over Pd supported on swellable organically-modified silica (SOMS),” Applied Catalysis B: Environmental, pp. 641–653, 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37136.