Ni@Pd core–shell nanoparticles modified fibrous silica nanospheres as highly efficient and recoverable catalyst for reduction of 4-nitrophenol and hydrodechlorination of 4-chlorophenol

Effect of metal precursor and pretreatment conditions on the catalytic activity of Ni/C in the aqueous phase hydrodechlorination of 1,1,2-trichloroethene

“…The decreasing of the reaction rate after 1 h of the TCE hydrodechlorination was observed in the case of all the catalysts (Table 2). Our results are in agreement with earlier studies of Dong et al [26] and could be explained by the progressive agglomeration of nickel particles under the reaction conditions and/or partial deactivation of nickel active sites by irreversible adsorption of products. The XRD experiments of the used catalysts showed that there are no significant changes in the size of the metal particles after hydrodechlorination reaction.…”

“…Zhou et al [29] postulated the volcano type of the relationship between the hydrodechlorination activity and metal particles size. On the other hand, recently published results of the aqueous phase hydrodechlorination of chloroorganic compounds indicate the beneficial role of the small metal particles on overall activity of the metallic catalysts [26,30,31]. Our results showed that the aqueous phase hydrodechlorination of 1,1,2-trichloroethene is structurally sensitive, and large nickel particles (*30 nm) are the most active for this reaction under the studied conditions.…”

“…However, the kinetics of TCE hydrodechlorination for Ni catalysts did not show a straight line characteristic for pseudo-first order reaction. Based on the literature data [26], the reaction kinetics was divided into two parts for each catalyst: before 60 min, with the highest value of the reaction rate constant k obtained for Ni(Cl)-H (Table 2) and from 60 to 150 min of the reaction, with the highest value of reaction rate constant k obtained for Ni(N)-H ( Table 2). The decreasing of the reaction rate after 1 h of the TCE hydrodechlorination was observed in the case of all the catalysts (Table 2).…”

Magnetically Separable and Sustainable Nanostructured Catalysts for Heterogeneous Reduction of Nitroaromatics

“…Reprinted with permission from [51]. The catalytic activity of the Ni@Pd/KCC-1 nanocatalysts was verified by the reduction of 4-nitrophenol to 4-aminophenol using NaBH4 as the reductant.…”

“…Such complicated approaches are neither efficient nor operative for the extensive production and applications that are particularly important in chemical industries [50]. These facts motivated continuous research improvements by the same group for the developments of highly active and magnetically recyclable Ni@Pd/KCC-1 nanocatalyst [51]. The immobilization of Ni@Pd NPs on the KCC-1 to fabricate the magnetic recyclable nanocatalysts could be promising for the purpose of preventing the aggregation of nanocatalysts, increasing the accessibility of the active sites and conferring the magnetic separation property to the nanocatalysts.…”