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

In this study, a novel fibrous nano-silica (KCC-1) based nanocatalyst (Ni@Pd/KCC-1) was synthesized by modifying KCC-1 using Ni@Pd core-shell nanoparticles (NPs). The Ni@Pd/KCC-1 was used in the catalytic reduction of 4-nitrophenol (4-NP) and hydrodechlorination (HDC) of 4-chlorophenol (4-CP). KCC-1, prepared by hydrothermal method, exhibited a dandelion-like shape, high surface area, and easy accessibility of active sites. The Ni@Pd NPs possessed a magnetic nickel (Ni) core with palladium (Pd) shell structural composite. Thus, use of Ni led to the reduced consumption of Pd without sacrificing the overall catalytic performance, simultaneously making it reusable as it could be conveniently recovered from the reaction mixture by using an external magnetic field. Immobilization of the Ni@Pd NPs on KCC-1 nanospheres not only prevented their aggregation, but also significantly enhanced the accessibility of the catalytic active sites. The Ni@Pd/KCC-1 nanocatalyst displayed excellent catalytic activities for both the reduction of 4-NP and the HDC of 4-CP under green conditions. The above-mentioned approach based on fibrous KCC-1 and Ni@Pd NPs provided a useful platform for the fabrication of noble metal-based cost-effective nanocatalyst with easy accessibility, and acted as a promising candidate for numerous catalytic applications. (C) 2014 Elsevier B.V. All rights reserved.