The voltammetric profile of preferentially shaped platinum nanoparticles has been used to analyze the different sites present on surface. For first time, this analysis made in NaOH solutions and revisited sulfuric perchloric acid media. comparison with profiles model surfaces, that is, single-crystal electrodes, allows assigning signals appearing voltammograms nanoparticle specific A good correlation between shape determined by TEM is obtained. characterized alkaline media, adsorbed species...

The study of the OH adsorption process on Pt single crystals is paramount importance since this adsorbed species considered main intermediate in many electrochemical reactions interest, particular, those oxidation that require a source oxygen. So far, it frequently assumed only takes place at potentials higher than 0.55 V (versus reversible hydrogen electrode), regardless surface structure. However, by CO displacement experiments, alternating current voltammetry, and Raman spectroscopy, we...

Reactivity towards methanol and formic acid electrooxidation on Pt nanoparticles with well characterised surfaces were studied compared the behaviour of single crystal electrodes basal orientations. Polyoriented preferential (100), (111) (100)-(111) synthesised, cleaned preserving its surface structure, employed to evaluate influence structure/shape these two relevant electrochemical reactions. The results pointed out that, in agreement fundamental studies electrodes, structure plays an...

The structure sensitive catalytic activity for oxygen reduction reaction (ORR) on shape-controlled Pt nanoparticles (NPs) is directly imaged using scanning electrochemical microscopy (SECM). We synthesize and compare four types of NPs: spherical, cubic, hexagonal, tetrahedral-octahedral. Our SECM images show the hexagonal NPs displaying highest ORR in two acid electrolytes. Meanwhile, cubic tetrahedral-octahedral drastically change their depending specific adsorption different anions...

The development of technologies for the recycling carbon dioxide into carbon-containing fuels is one major challenges in sustainable energy research.

In this paper we will review the state-of-the-art in application of shape-controlled metal nanoparticles Electrocatalysis, especially reactions interest PEMFCs such as O2reduction and CO, methanol, ethanol formic acid electrooxidations. particular, focus our attention on platinum (Pt), gold (Au) palladium (Pd) nanoparticles. addition, electrocatalytic applications Pt-based alloy be also reviewed. The results reported highlight how important can controlling shape nanocatalyst effective...

The synthesis of shape-controlled nanoparticles is currently a hot research topic. However, from an applied point view, there still lack easy, cheap, and scalable methodologies. In this communication we report, for the first time, cubic platinum with very high yield using water-in-oil microemulsion method, which unlike others, such as colloidal fulfills previous requirements. This shape/surface structure control determined by concentration HCl in water phase microemulsion. results reported...

Tetrahexahedral Pt nanocrystals (THH NCs) bounded by high-index facets possess a high density of active sites and display therefore higher catalytic activity in comparison with those enclosed low-index facets. In the current communication, we report, for first time, decoration THH NC surfaces using Bi adatoms have demonstrated that decorated NCs toward HCOOH electrooxidation has been drastically enhanced bare NCs. It also revealed all coverages investigated always exhibits is about double...

In the present paper, preferentially oriented (111) Pt nanoparticles (mostly octahedral and tetrahedral, namely {111}Pt nanoparticles) have been characterized compared with a Pt(554) single-crystal electrode as their voltammetric features are quite similar in 0.5 M H2SO4. The anion Bi adsorption behaviours suggest that contain relatively wide hexagonal domains also isolated sites which could adsorb solely hydrogen. step decoration has successfully extended to modify defects of without...

The oxidation of ammonia on platinum surfaces is a structure sensitive reaction that takes place almost exclusively Pt(100) sites. This report shows how dependent the activity different arrangements (100) sites platinum. effect two-dimensional domains has been addressed by using stepped having terraces with geometry, either (111) and (110) steps. results were compared those obtained from or symmetry monatomic steps, thus representing monodimensional domains. observed behavior confirms...

A new method for in situ surface characterization of preferentially oriented platinum nanoparticles is presented. The based on the use structure-sensitive reactions such as redox behavior underpotential and spontaneous deposition adatoms. Examples its Pt synthesized by different methods are given. has been also employed to rationalize these ammonia electro-oxidation a basic medium.

The electrocatalytic properties of palladium nanocubes towards the electrochemical oxidation formic acid were studied in H(2)SO(4) and HClO(4) solutions compared with those spherical Pd nanoparticles. cubic nanoparticles characterized by transmission electron microscopy (TEM) X-ray diffraction (XRD). intrinsic both shown to be strongly dependent on amount metal deposited gold substrate. Thus, properly compare activity systems (spheres nanocubes), sample has optimized avoid problems due a...

Decorating platinum nanoparticles having preferential (100) orientation with palladium adatoms in the submonolayer range enhances their catalytic performance electrooxidation of formic acid (see picture). Moreover, as are deposited a similar way to that used analogous single-crystal studies, proper relationships between and nanoparticle catalysis or electrocatalysis can be established. Detailed facts importance specialist readers published "Supporting Information". Such documents...

Formate adsorption: Fast electrochemical techniques allow the detection of formate as adsorbed species from formic acid on platinum single-crystal electrodes (see picture). Additionally, oxidation current for is directly proportional to coverage, which indicates that active intermediate. Detailed facts importance specialist readers are published "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted by authors. Please note: The...

Ethanol oxidation on platinum nanoparticles with well-characterized surfaces is studied using cyclic voltammetry and FTIR techniques. Their behavior compared that obtained for single crystal electrodes, in order to rationalize their performance understand the effects of surface structure anion adsorption reactivity. The results clearly demonstrate there are strong measured current mechanism. Thus, main product ethanol (111) preferentially oriented Pt acetic acid, amount CO2 produced can be...