Aqueous-Phase Hydrodechlorination of Trichloroethylene over Pd-Based Swellable Organically Modified Silica: Catalyst Deactivation Due to Sulfur Species

• DOI: 10.1021/acs.iecr.8b05979
• Publication Date: 2019-02-14T21:32:44Z
• Authors: Gokhan Celik; Saurabh A. Ailawar; Seval Gunduz; Jeffrey T. Miller; Paul L. Edmiston; Umit S. Ozkan
• Keywords: Aqueous two-phase system; Physisorption

One of the problems catalytic water treatment systems is that sulfur-containing species present in contaminated have a detrimental effect on performance because strong interactions sulfur with active metal sites. In order to address these problems, our research has focused developing poison-resistant system by using novel material, namely, swellable organically modified silica (SOMS), as catalyst scaffold. Our previous investigations demonstrated developed was resistant chloride poisoning, leaching, and carbon deposition under reaction conditions. This study examines tolerance for hydrodechlorination (HDC) trichloroethylene (TCE) subjecting Pd-incorporated samples different species, including sulfates (SO42–), bisulfides (HS–), hydrogen sulfide (H2S). The pristine sulfur-treated catalysts were then tested aqueous- gas-phase HDC TCE characterized several techniques, N2 physisorption, X-ray photoelectron spectroscopy (XPS), extended absorption fine structure (EXAFS), temperature-programmed (TPrxn) H2. also performed Pd/Al2O3, commercially used catalyst, basis comparison. activity characterization results revealed Pd/Al2O3 underwent deactivation due exposure compounds. Pd/SOMS, however, exhibited better resistance aqueous sulfates, bisulfides, H2S. addition, removal from completely poisoned found be more facile Pd/SOMS than Pd/Al2O3. poisoning attributed stem characteristics SOMS, such swelling ability extreme hydrophobicity.