Morphology-Controlled Synthesis of Palladium Nanostructures by Sonoelectrochemical Method and Their Application in Direct Alcohol Oxidation

Abstract

A simple sonoelectrochemical method was used to realize the morphology-controlled synthesis of palladium nanostructures at room temperature. The palladium spherical nanoparticles, multitwinned particles, and spherical spongelike particles (SSPs) were successfully prepared in the presence of different surfactants or polymers. It was found that the size and shape of the Pd nanostructures could be controlled by varying current density and pH value of the precursor solution. The Pd nanostructures were characterized by transmission electron microscopy, high-resolution transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive X-ray, and X-ray diffraction. The possible formation mechanism was discussed. In addition, the electrocatalytic properties of the Pd nanostructures for direct alcohol oxidation in alkaline media were systematically investigated. The results showed that SSPs had a higher electrochemical active surface and result in more stable and better electrocatalytic properties than other Pd nanostructures for the ethanol electrooxidation.

Catalytic oxidation of carbon monoxide over supported palladium nanoparticles

“…It appears that these small primary nanoparticles are interconnected with one another to form larger secondary spherical sponge-like architectures with recognizable boundaries or voids between the component subunits. The Pd particle sizes measured from the TEM are very similar with the result obtained from XRD by Shen et al (2009). It is reported that the small size of the PVP-synthesized Pd nanoparticles, suggesting much smaller activation energy for CO oxidation on Pd/alumina (Stara et al 1995).…”

“…Lim et al (2007) reported that PVP is strongly bound to the (100) facets of Pd and affect the relative growth rates of different facets, this might be favored for multi-twinned particles. The sponge-like structure is also reported with high magnification micrograph, which is built up by primary nanoparticles with an average dimension of 5 nm (Shen et al 2009). It appears that these small primary nanoparticles are interconnected with one another to form larger secondary spherical sponge-like architectures with recognizable boundaries or voids between the component subunits.…”

Recent Development of Pd-Based Electrocatalysts for Proton Exchange Membrane Fuel Cells

“…With similar technique, Zhou et al [14] prepared the Pd NCs not limited to the tetrahexahedral crystals. Shen et al [15] used a sonoelectrochemical method to prepare Pd spherical nanoparticles, multitwinned particles, and spherical spongelike particles. Ding et al [16] prepared single crystalline Pd nanocubes with the polyol method.…”

Molecular Palladium Precursors for Pd0 Nanoparticle Preparation by Microwave Irradiation: Synthesis, Structural Characterization and Catalytic Activity

“…[3] Palladium nanoparticles (Pd NPs) are of current interest due to their large surface/volume ratio and the possible control over their size and shape, which influences their catalytic properties. [4,5] So far, many methods have been reported to prepare monodispersed Pd nanoparticles, which include chemical reduction of palladium salts or complexes [6] by reaction with molecular hydrogen, metal hydrides or by means of the polyol process, [5] or sonoelectrochemical methods [7] whereby different surfactants, polymers or ionic liquids have been used to prevent agglomeration and to impose a chemical control over the morphological features of the particles. [8] Microwave irradiation of ionic or thermally labile precursors offers a facile, fast and green pathway to synthesize metal and metal oxide nanoparticles as the reaction durations are drastically reduced due to instantaneous heating of the reaction medium and formation of hot spots in the reaction mixture, which can be tuned by choosing solvents with desired polarity and dielectric properties.…”