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.
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. Moreover, flow experiments, regardless of whether the SOMS-supported Pd catalysts were pre-reduced or not, yielded similar steady-state conversions, suggesting that Pd(2+) is rapidly reduced by H2 dissolved in water during approach to steadystate. In-situ characterization performed under reaction conditions using time-resolved X-ray absorption spectroscopy confirmed the reduction of Pd(2+) species to Pd(0) by dissolved H2. Overall, this study shows economic viability of hydrodechlorination of TCE using Pd/SOMS by eliminating the need for an external swelling-agent as well as a catalyst pre-reduction step.


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 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...
The effects of alkali promoters on the dynamics of hydrogen chemisorption and syngas reaction kinetics on Ru/SiO2 surfaces
Üner, Deniz; Pruski, M; King, TS (1997-01-01)
The dynamics of chemisorbed hydrogen on unpromoted and promoted Ru/SiO2 catalysts was studied by means of single pulse and selective excitation H-1 NMR spectroscopy. Dynamic NMR studies indicated a reduced mobility of hydrogen in the presence of alkali promoters (Na and K) at high loadings (65 atomic %). On unpromoted Ru/SiO2 catalysts, the line due to hydrogen-on-metal was homogeneously broadened at pressures above 0.5 Torr H-2. Similar behavior was observed on promoted Ru/SiO2 catalyst with 66 atomic % K....
The effect of para-cyclophane structure on cyclacenes
Türker, Burhan Lemi (2000-02-01)
Semiempirical molecular orbital treatment at the level of AMI type has been performed on the Huckel type cyclacenes having the normal and the skew type para-cyclophane moiety embedded into their structures. The cyclophane effect is found to be operative on the lower members by veiling the cryptoannulenic effect which is influential on the heats of formation values and the frontier molecular orbital energies of the higher members as well as the parent cyclacenes.
Investigation of the effect of alumina binder addition to Pd/SO42− − ZrO2 Catalysts during sol−gel synthesis
Sinha Majumdar, Sreshtha; Çelik, Gökhan; Ozkan, Umit (2016-01-01)
We have incorporated alumina into palladium catalysts supported on sulfated zirconia (Pd/SZ) during sol-gel synthesis for application in a washcoat for NOx emissions control in natural gas-fired lean-burn engines. In situ incorporation of the adhesivity-enhancing binder, alumina, during the sol-gel synthesis of the Pd/SZ catalyst demonstrated significantly improved NOx reduction activity of the previously reported dual-catalyst bed when compared to the conventional ex situ mode of binder addition in a slurr...
Citation Formats
S. Ailawar et al., “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),” APPLIED CATALYSIS B-ENVIRONMENTAL, pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/91644.