Influence of preparation procedure on catalytic activity of PdBEA zeolites in aqueous phase hydrodechlorination of 1,1,2-trichloroethene

Abstract

Pd-loaded BEA zeolites containing 1 wt % of Pd were prepared by a two-step postsynthesis method (PdSiBEA and PdSiAlBEA) and a conventional wet impregnation (PdHAlBEA). Modification of BEA zeolite resulted in the introduction of Pd ions into zeolite framework as pseudo-tetrahedral Pd(II) and extra-framework octahedral Pd(II) evidenced by XRD, DR UVvis and TPR measurements. Calcination of as prepared zeolites in air at 773 K for 3 h and then reduction in 10 % H 2 /Ar flow at 873 K for 3 h led to obtain red-C-PdSiBEA, red-C-PdSiAlBEA and red-C-PdHAlBEA zeolites with different Pd nanoparticles size distributions showed by TEM. These zeolite materials were found to be active catalysts in aqueous-phase hydrodechlorination of 1,1,2-trichloroethene (TCE). The conducted catalytic reactions have demonstrated that the rate and course of TCE hydrodechlorination depend on the catalysts preparation method and Pd nanoparticles size.

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

“…It is an elimination-based remediation technique in which chlorinated compounds react with H 2 and are catalytically converted to chloride-free hydrocarbons and HCl. There has been ongoing research on HDC of chlorinated compounds where promising conversions and catalytic activities were obtained with the palladium-based state-of-the-art catalysts. − The existing hydrodechlorination catalysts reported in the literature, however, suffer from catalyst poisoning due to anionic species present in real groundwater, inhibition by the unavoidable reaction product HCl, the formation of carbonaceous species on active sites, and active metal leaching. ,,− In our present contribution, studies were performed to confirm whether active metals can be selectively located in the swollen matrix of SOMS and to understand the behavior of the active sites with respect to different reactive environments. Catalytic activity experiments and characterization studies were performed to examine properties of SOMS and Pd-incorporated SOMS in their unswollen and swollen states.…”

Promoting Light Hydrocarbons Yield by Catalytic Hydrodechlorination of Residual Chloromethanes Using Palladium Supported on Zeolite Catalysts

“…As the NPs are isolated from others NPs due to their encapsulation on the zeolite cages and different channels, the catalytic activity can be improved, as well as the stability [20]. Due to this, zeolites are commonly used in liquid phase hydrodechlorination reactions [13,21,22], however, fewer studies have been applied to gas phase HDC [23][24][25][26]. In those gas-phase studies, conversion usually decreased after a few hours on stream, high selectivities to methane were obtained, and/or very low reactant inlet concentrations (below 100 ppm) were used [23,27,28].…”

MoP@C Supported on Absorbent Cotton as a Highly Efficient Catalyst towards Hydrodechlorination Reaction

“…Oyama found that the catalytic performance of MoP/Al 2 O 3 was superior to that of Ni‐Mo‐S/Al 2 O 3 for hydrotreating. Therefore, the potential of transition metal phosphides (TMPs) as catalysts for hydrodesulfurization (HDS),, hydrodenitrification (HDN),, Hydrodeoxygenation (HDO), and hydrodechlorination (HDC) has been explored. Most researchers agree that phosphorus atoms are doped into the transition metal lattice in TMPs.…”