Treatment of chlorophenols-bearing wastewaters through hydrodechlorination using Pd/activated carbon catalysts

Catalytic hydrodechlorination of p-chloro-m-cresol and 2,4,6-trichlorophenol with Pd and Rh supported on Al-pillared clays

“…The C balance closure was around 95% with the two catalysts. These results are consistent with the reported in previous works on HDC of other chlorophenols with Pd and Rh supported on pillared clays [25][26][27][28], Al 2 O 3 [19] or activated carbon [6,46,47]. The different reactivity of chlorocresols and chlorophenols has been associated to the presence of the methyl substituent that reduces the reactivity by the inductive effect [24,48].…”

Catalysts based on large size-controlled Pd nanoparticles for aqueous-phase hydrodechlorination

“…In a previous work [65], we proposed a reaction scheme for 4-CP HDC with Pd/AC catalysts. According to that scheme, 4-CP is dechlorinated to phenol in a first step and then cyclohexanone and cyclohexanol result from further hydrogenation of phenol.…”

Complete dechlorination of pentachlorophenol using palladized bacterial cellulose in a rotating catalyst contact reactor

“…It may be noted that Hoke et al used very high concentration of chlorophenol (e.g., ∼78 mM of 4-CP) and hence the corresponding concentration of HCl released following complete dechlorination was very high (∼2.8 g L −1 HCl) [19]. Calvo et al, studied hydrodechlorination of 100 mg L −1 of 2-chlorophenol and 4-chlorophenol (stoichiometric HCl concentration ∼28 mg L −1 ) using Pd/C catalyst [15]. Complete dechlorination of chlorophenols to cyclohexanol was reported by the authors without the addition of a base.…”

“…However, advantages of bimetallic system such as high rate of reaction, efficiency, mild reaction conditions, and requirement for minimal follow-up treatment, will be defeated if reactor design does not permit the reuse and recovery of expensive catalysts such as palladium through immobilization on suitable support matrices. Hydrodechlorination of chlorophenols using supported palladium has been reported profusely in the literature [14][15][16][17][18][19]. Various types of support materials such as carbon, chitin, chitosan, amino acids, alumina, silica, zeolites, and metal oxides such as TiO 2 , MgO, ZrO 2 have been used for the immobilization of palladium [14,18,20].…”