Au electrocatalysis

Poly (2-hydroxy-3-aminophenazine) Metal clusters (Au) Electrocatalysis 639, 640... 

Motoo S, Shibata M, Watanabe M. 1980. Electrocatalysis by ad-atoms. Part VI. Enhancement of CO oxidation on Pt(subs) and Pt-Au(subs) electrodes by Sn ad-atoms. J Electroanal Chem 110 103-109. 

Pronkin SN, Tsirlina GA, Petrii OA, Vassiliev SY. 2001. Nanoparticles of Pt hydrosol immobilized on Au support An approach to the study of structural effects in electrocatalysis. Electrochim Acta 46 2343-2351. 

In addition, it sustains CO electro-oxidation at relatively low overpotential, and there are crystal face dependences for both the ORR and CO oxidation. Since Au is also a system that exhibits both particle size and support effects in heterogeneous catalysis, it provides an interesting model system for smdying such effects in electrocatalysis. 

Adzic RR, Markovic NM, Vesovic, VB. 1984. Structural effects in electrocatalysis Oxygen reduction on the Au(lOO) single crystal electrode. J Electroanal Chem 165 105-120. 

Figure 17.11 Schematic representation of an approach for achieving efficient electrocatalysis of glucose oxidation by glucose dehydrogenase on Au nanoparticles tethered on an Au electrode. The nanoparticles are modified with a PQQ-capped linker that interacts with the unoccupied PQQ site of cofactor-deficient glucose dehydrogenase [Zayats et al., 2005].

Figure 6.7 illustrates the voltammetric response of the third-generation SOD-based 02 biosensors with Cu, Zn-SOD confined onto cystein-modified Au electrode as an example. The presence of 02" in solution essentially increases both the cathodic and anodic peak currents of the SOD compared with its absence [150], Such a redox response was not observed at the bare Au or cysteine-modified Au electrodes in the presence of 02". The observed increase in the anodic and cathodic current response of the Cu, Zn-SOD/cysteine-modified Au electrode in the presence of 02 can be considered to result from the oxidation and reduction of 02, respectively, which are effectively mediated by the SOD confined on the electrode as shown in Scheme 3. Such a bi-directional electromediation (electrocatalysis) by the SOD/cysteine-modified Au electrode is essentially based on the inherent specificity of SOD for the dismutation of 02", i.e. SOD catalyzes both the reduction of 02 to H202 and the oxidation to 02 via a redox cycle of its Cu (II/I) complex moiety as well as the direct electron transfer of SOD realized at the cysteine-modified Au electrode. Thus, this coupling between the electrode and enzyme reactions of SOD could facilitate the development of the third-generation biosensor for 02". ...

F. Patolsky, T. Gabriel, and I. Willner, Controlled electrocatalysis by microperoxidase-11 and Au-nano-particle superstructures on conductive supports. J. Electroanal. Chem. 479, 69-73 (1999). 

K. Nishimura, K. Kunimatsu, and M. Enyo, Electrocatalysis on Pd + Au alloy electrodes 3. IR spectroscopic studies on the surface species derived from CO and CH30H in NaOH solution, J. Electroanal. Chem. 260, 167-179 (1989). 

The lure of new physical phenomena and new patterns of chemical reactivity has driven a tremendous surge in the study of nanoscale materials. This activity spans many areas of chemistry. In the specific field of electrochemistry, much of the activity has focused on several areas (a) electrocatalysis with nanoparticles (NPs) of metals supported on various substrates, for example, fuel-cell catalysts comprising Pt or Ag NPs supported on carbon [1,2], (b) the fundamental electrochemical behavior of NPs of noble metals, for example, quantized double-layer charging of thiol-capped Au NPs [3-5], (c) the electrochemical and photoelectrochemical behavior of semiconductor NPs [4, 6-8], and (d) biosensor applications of nanoparticles [9, 10]. These topics have received much attention, and relatively recent reviews of these areas are cited. Considerably less has been reported on the fundamental electrochemical behavior of electroactive NPs that do not fall within these categories. In particular, work is only beginning in the area of the electrochemistry of discrete, electroactive NPs. That is the topic of this review, which discusses the synthesis, interfacial immobilization and electrochemical behavior of electroactive NPs. The review is not intended to be an exhaustive treatment of the area, but rather to give a flavor of the types of systems that have been examined and the types of phenomena that can influence the electrochemical behavior of electroactive NPs. 

Pd then plates onto the terrace sites (Fig. 11). On Au(lll), only terrace sites are exposed. In this manner, the surface electrochemical properties of the subject compounds at the steps and on the terraces surfaces can be compared. It should be recalled that aromatic molecules chemisorb only on Pd but not on Au " the expectation is then that the lower the Pd coverage, the lower the amount (and subsequent electrocatalysis) of chemisorbed benzene. 

Thus, characterization of surfaces is important to the field of catalysis and electrocatalysis of nanoparticles. In the past 30 years, numerous electron and ion spectroscopic techniques, in addition to microscopic or imaging techniques, have been established to provide this information. Figure 1 provides high-resolution transmission electron microscopy (TEM) images of a practical (real), high-surface-area, Au/anatase-Ti02 heterogeneous catalyst that show the small Au nanoparticles... 

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