156 research outputs found
Cathodic Corrosion: A Quick, Clean, and Versatile Method for the Synthesis of Metallic Nanoparticles**
A simple and effective method for the synthesis of nanoparticles is reported based on extreme cathodic polarization of a metal, formation of cation-stabilized metal anions, and their agglomeration (see picture). The improved catalytic activity of these nanoparticles in the oxidation of carbon monoxide as well as methanol is shown using platinum.<br/
Electrochemical Characterization of Clean Shape-Controlled Pt Nanoparticles Prepared in Presence of Oleylamine/Oleic Acid
A collection of shape-controlled Pt nanoparticles has been prepared using two different and previously described methodologies, both using oleylamine/oleic acid as capping material/solvent. A new decontamination protocol is presented to effectively clean the surface of the different nanoparticles thus allowing a full exposure of their surface area and consequently to make the most of their surface structure dependent reactivity. Subsequently, the clean shape-controlled Pt nanoparticles have been electrochemically characterized and their electrocatalytic properties evaluated towards some surface structure reactions of interest. The results indicate that the full characterization of the surface structure cannot be done exclusively by the available microscopy techniques, since it is very difficult to determine the presence of surface defects. Additional surface characterization probes, such as those provided by electrochemical surface sensitive reactions, have been used to assess the surface structure of the samples.This work has been financially supported by the MICINN (Feder) of Spain and Generalitat Valencia through Projects CTQ2013-44083-P and PROMETEOII/2014/013, respectively
Electrocatalytic enhancement of formic acid oxidation reaction by acetonitrile on well-defined platinum surfaces
Catalysis and Surface Chemistr
Characterization of Au and Bimetallic PtAu Nanoparticles on PDDA-Graphene Sheets as Electrocatalysts for Formic Acid Oxidation
Mimicking the Microbial Oxidation of Elemental Sulfur with a Biphasic Electrochemical Cell
The
lack of an artificial system that mimics elemental sulfur (S8)
oxidation by microorganisms inhibits a deep mechanistic understanding of the
sulfur cycle in the biosphere and the metabolism of sulfur-oxidizing
microorganisms. In this article, we present a biphasic system that mimics
biochemical sulfur oxidation under ambient conditions using a liquid|liquid
(L|L) electrochemical cell and gold nanoparticles (AuNPs) as an interfacial
catalyst. The interface between two solvents of very different polarity is an
ideal environment to oxidise S8, overcoming the incompatible solubilities of the hydrophobic reactants
(O2 and S8) and hydrophilic products (H+, SO32–,
SO42–, etc.). The interfacial AuNPs provide a
catalytic surface onto which O2 and S8 can adsorb.
Control over the driving force for the reaction is provided by polarizing the
L|L interface externally and tuning the Fermi level of the interfacial AuNPs by
the adsorption of aqueous anions.</p
Electrochemical characterization of irreversibly adsorbed germanium on platinum stepped surfaces vicinal to Pt(100)
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