Publisher Summary This chapter discusses chemical oxidations, oxidations on acidic surfaces, and photoionizations. The formation of cation radicals in solution is also discussed. The chapter outlines the experimental techniques that have been used to study cation radicals and the type of information that can be obtained about their behavior. Examples of such investigations are provided. A large number of electrochemical techniques is available for producing and studying cation radicals (or other electrogenerated). Their instrumentation, techniques, and theory are described. The electrochemical techniques can be separated into two classes: the microelectrode or voltammetric techniques and the bulk electrolysis or coulometric techniques. Detailed descriptions of physical properties of cation radicals are presented in the chapter. Cation radicals react with a variety of nucleophiles. Substitution often occurs, but there are many examples in which electron transfer occurs either entirely or in part.

Formation, Properties and Reactions of Cation Radicals in Solution

The electrochemical deposition of platinum on an Au(111) single-crystal electrode in acidic solutions containing H2PtCl6 was studied using an electrochemical scanning tunneling microscope (STM) and electrochemical quartz crystal microbalance (EQCM). The STM investigation showed an ordered adlayer of PtCl62- on the electrode surface during the electrochemical deposition of platinum and a Pt(111)-(1×1) structure on the electrode surface after the electrode was rinsed with a Pt complex-free solution. Formations of the Pt(111) bulk phase and surface structure of Pt(111)-(1×1) were confirmed by X-ray diffraction (XRD) and the underpotential deposition of copper and hydrogen, respectively.

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Electrochemical epitaxial growth of a pt(111) phase on an au(111) electrode

Experimental investigation of the hydrothermal geochemistry of platinum and palladium: I. Solubility of platinum and palladium sulfide minerals in NaCl/H2SO4 solutions at 300°C

A novel electroless Pt deposition method was exploited by employing the galvanic replacement process occurring between the Mn3O4 surface and PtCl42– complexes. The newly discovered process provides a simple protocol to produce the catalytic nanocomposite, in which a high density of ultrafine Pt nanocrystals is stably immobilized in a homogeneously dispersive state on the surface of Mn3O4 nanoparticles. When the eletrocatalytic activity was tested for the oxygen reduction reaction, which limits the rate of the overall process in proton-exchange membrane fuel cells, the resulting Pt/Mn3O4 nanocomposite showed highly enhanced specific activity and durability, compared with those of the commercial Pt/C catalyst.

Electroless Pt deposition on Mn3O4 nanoparticles via the galvanic replacement process: electrocatalytic nanocomposite with enhanced performance for oxygen reduction reaction.

Electrodeposition and properties of nanostructured platinum films studied by quartz crystal impedance measurements at 10 MHz

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The Redox System Platinum(0)/Platinum(II)/Platinum(IV) with Chloro and Bromo Ligands.

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Studies on the Possible Effects of Adsorption on the Product Distribution of Organic Electrode Reactions. III. Competition Processes and Mutual Interactions Between Two Substrates in Anodic Acetoxylation.

Rodney G. Wilkinson

Papers

The Redox System Platinum(0)/Platinum(II)/Platinum(IV) with Chloro and Bromo Ligands.

Studies on the Possible Effects of Adsorption on the Product Distribution of Organic Electrode Reactions. III. Competition Processes and Mutual Interactions Between Two Substrates in Anodic Acetoxylation.