RC-SECM

RC-SECM Redox competition mode scanning electrochemical microscopy... 

Okunola AO, Nagaiah TC, Chen X, Eckhard K, Schuhmaim BM (2009) Visualization of local electrocatalytic activity of metalloporphyrins towards oxygen reduction by means of redox competition scanning electrochemical microscopy (RC-SECM). Electrochim Acta 54(22) 4971 978... 

Smaller catalyst libraries have been investigated by several other research groups. For example, Chen et al. electrodeposited a small library of noble metals (Pt, Ru, Rh, and Au) by means of a capillary-based droplet cell onto carbon nanotubes predeposited on glassy carbon by electrophoretic accumulation, and screened their ORR activity in a 0.1 M phosphate solution using the oxygen competition mode (pH = 6.7) [68, 82]. Our group employed RC-SECM to map the ORR activity of Pt, and Pt-based alloy nanoparticles, including core-shell structures... 

Eckhard K, Chen X, Turcu F, Schuhmann W (2006) Redox competition mode of scanning electrochemical microscopy (RC-SECM) for visualisation of local catalytic activity. Phys Chem Chem Phys 8(45) 5359-5365... 

Kamicka, K., Eckhard, K., Guschin, D. A., Stoica, L., Kulesza, P. J., Schuhmann, W. Visualisation of the local bio-electrocatalytic activity in biofuel ceU cathodes by means of redox competition scaiming electrochemical microscopy (RC-SECM). Electrochem Commun 2007, 9,1998-2002. 

When the species to be studied cannot be conveniently generated at an electrode and no product of the electrode reaction can be detected, then SECM shielding (Figure 16.3d) can be used to screen an array. In shielding, the same reaction occurs at the tip and the substrate so that the current at the tip is decreased compared to what would be observed with an insulating substrate. " Thus the tip is shielded by and competes with the substrate for the same reactant A reactant in bulk solution can be studied by noting how well the substrate competes with the tip for consumption of the reactant This approach, also called redox competition (RC-SECM), was used to study the ORR on model Pt and An catalyst spots as an alternative to TG/SC. " ... 

Guadagnini, L., Maljusch, A., Chen, X., Neugebauer, S., Tonelli, D., Schuhmann, W. Visualization of electrocatalytic activity of microstructured metal hexacyanoferrates by means of redox competition mode of scanning electrochemical microscopy (RC-SECM). Electrochim. Acta 2009, 54, 3753-3758. 

FIGURE 14.10 RC SECM image of a bilirubin oxidase/Os polymer spot on a glassy carbon chip in 20 mM phosphate citrate buffer (pH 6). The O2 reduction current at the SECM tip (25 pm diameter Pt disk electrode) is plotted as a function of the (x, y) position. (Reprinted with permission from Ref. [67]. Copyright 2007, Elsevier.)... 

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