Au@PdAg core-shell nanotubes as advanced electrocatalysts for methanol electrooxidation in alkaline media

Porous Noble Metal Electrocatalysts: Synthesis, Performance, and Development

Active sites (intrinsic activity, quantity, and distribution), electron transfer, and mass diffusion are three important factors affecting the performance of electrocatalysts. Composed of highly active components which are built into various network structures, porous noble metal is an inherently promising electrocatalysts. In recent years, great efforts have been made to explore new efficient synthesis methods and establish structural-performance relationships in the field of porous noble metal electrocatalysis. In this review, the very recent progress in strategies for preparing porous noble metal, including innovation and deeper understanding of traditional methods is summarized. A discussion of relationship between porous noble metal structure and electrocatalytic performance, such as accessibility of active sites, connectivity of skeleton structures, channels dimensions, and hierarchical structures, is provided.

Morris M, G. Lyons M, Gun’ko YK. One Dimensional AuAg Nanostructures as Anodic Catalysts in the Ethylene Glycol Oxidation

Direct alcohol fuel cells are highly promising as efficient power sources for various mobile and portable applications. However, for the further advancement of fuel cell technology it is necessary to develop new, cost-effective Pt-free electrocatalysts that could provide efficient alcohol oxidation and also resist cross-over poisoning. Here, we report new electrocatalytic materials for ethylene glycol oxidation, which are based on AuAg linear nanostructures. We demonstrate a low temperature tunable synthesis that enables the preparation of one dimensional (1D) AuAg nanostructures ranging from nanowires to a new nano-necklace-like structure. Using a two-step method, we showed that, by aging the initial reaction mixture at various temperatures, we produced ultrathin AuAg nanowires with a diameter of 9.2 ± 2 and 3.8 ± 1.6 nm, respectively. These nanowires exhibited a high catalytic performance for the electro-oxidation of ethylene glycol with remarkable poisoning resistance. These results highlight the benefit of 1D metal alloy-based nanocatalysts for fuel cell applications and are expected to make an important contribution to the further development of fuel cell technology.

High quality electrocatalyst by Pd-Pt alloys nanoparticles uniformly distributed on polyaniline/carbon nanotubes for effective methanol oxidation

In the present work, Pd-Pt nanoparticle/polyaniline/carbon nanotube (NP/PANI/CNT) composites, synthesized through the uniform distribution of Pd-Pt NPs, whose single size was controlled to 2-4 nm by citric acid, on a PANI/CNT compound, served as the electrode catalysts for effective methanol oxidation. The structural characteristics were identified by x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy, and revealed that the Pt₆₅Pd₃₅ NP/PANI/CNT composite displayed superior electrocatalytic oxidation performance and vitality in various Pd-Pt NPs. The results indicated that as an excellent anode catalyst the complex would have application prospects for effective methanol oxidation.

Surfactant-free synthesis of porous Au by a urea complex

We report a facile surfactant-free synthetic method to obtain porous and hollow Au nanoparticles using only urea and HAuCl₄·4H₂O as precursors at 200 °C. The formation mechanism was investigated through X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. Moreover, the prepared Au nanocrystals present superior catalytic performance for the reduction of 4-nitrophenol in comparison with solid Au nanoparticles. The catalytic efficiency of porous and hollow Au was nearly 6 times higher than that of Au nanoparticles. Furthermore, the porous and hollow Au maintained excellent stability even after 10 catalytic cycles. Therefore, the as-synthesized porous Au nanoparticles will have potential applications in organic catalysis, biosensing, drug delivery, water pollutant removal, and so on.

A gold–urea complex was incinerated to transform into porous hollow gold nanoparticles (PHAuNPs), and the PHAuNPs present high catalytic activity.