Hierarchical structure based on Pd(Au) nanoparticles grafted onto magnetite cores and double layered shells: enhanced activity for catalytic applications

Abstract

This work introduces a novel sandwich-like structured nanocatalyst, which shows a large specifi c surface area, good dispersity and enhanced synergistic eff ects between CeO 2 and noble metals. This synthetic strategy is an eff ective method for the preparation of highly effi cient sandwich-like mesoporous catalysts.We report the creation of highly efficient sandwich-like structured nanocatalysts consisting of magnetic Fe 3 O 4 cores, porous SiO 2 and CeO 2 shells and coated with noble metal nanoparticles (NMNPs). The nanocatalysts possess uniform sizes, variable shell compositions and thicknesses, adjustable noble metal nanoparticle coatings, tunable morphologies and good structural stability, and can be used as unique catalysts with extremely high catalytic activity and stability for the 4-nitrophenol reduction reaction due to their structural features with multiple interactions and strong synergistic effects between the noble metal nanoparticles and the cerium oxide shells. The designed double shelled Fe 3 O 4 @SiO 2 @CeO 2 /M nanocatalysts can be used as novel catalyst systems with highly efficient catalytic performance for various catalytic reactions depending on their shell components and noble nanoparticle coating. The synthetic strategy provides a new methodology to design high-performance and recyclable nanocatalysts.

Basic concepts and recent advances in nitrophenol reduction by gold- and other transition metal nanoparticles

“…A combination of magnetic Fe 3 O 4 NPs, porous SiO 2 and CeO 2 shells has also been used to support noble metal NP, forming sandwich-like structured mono-dispersed microspheres of Fe 3 O 4 @SiO 2 @CeO 2 /M (M = Au, Pd and Au-Pd) [80]. Their catalytic properties were investigated for 4-NP reduction.…”

“…The common and most efficient way for the reduction of 4-NP is to introduce NaBH 4 as a reductant and a metal catalyst such as AuNPs [12], AgNPs [13], PdNPs [14], PtNPs [15] and NiNPs [16]. Compared with other metal catalysts, AuNPs have two unique properties: (i) the catalytic activity of gold is directly related to the particle size, and the catalytic activity is only observed at the nanometric scale but not micrometric scale; (ii) Au catalysts are active under mild conditions, even at ambient temperature or less.…”

The {0 0 1} facets-dependent superior photocatalytic activities of BiOCl nanosheets under visible light irradiation

“…The morphology of the photocatalysts is an important factor that may influence the visible light catalytic activities [15][16][17][18]. The morphologies of the as-obtained BiOCl samples synthesized in the presence of mannitol, tartaric acid, and P123 were measured by FE-SEM ( Fig.…”

Effect of hydrothermal reaction time and calcination temperature on properties of Au@CeO2 core–shell catalyst for CO oxidation at low temperature

“…4b. Four main peaks at 917.3 eV, 908.2 eV, 903.6 eV, and 901.9 eV correspond to the a1, a2, a3, and a4 components of Ce 3d 3/2 , while the other four peaks located at 899.3 eV, 890.1 eV, 887.6 eV, and 883.2 eV correspond to b1, b2, b3, and b4 of Ce3d 5/2 , respectively [22,23]. The signals a3 and b3 are attributed to Ce 3?…”