Electrochemical combinatorial method

The coupling between electrochemical measurement and different techniques that allows for superficial screening, the so-called electrochemical combinatorial method, has played an important role in the search for new catalysts with application in fuel cells [120-126]. 

Preparation of Memfield resin-bound nitro acetates, which is a suitable bndding block for the development of combinatorial solid phase synthesis, is repotted. The anion of ethyl nitro acetate is generated in DMF by an electrochemical method using Pt cathode, magnesium rod anode, and tetrabutylairunonium bromide as an electrolyte. Alkylaton of this anion with alkyl hahdes gives mono-alkylated products in 80% yield." ... 

Yoshida, J.-I., Cation Flow method a new approach to conventional and combinatorial organic syntheses using electrochemical micrqflow systems, J. Am. 

The research of Mallouk and Smotkin [45] considered combinatorial catalyst development methods. In the combinatorial research, the tools of electrochemical analysis (steady-state and dynamic voltammetry, chronoamperometry, scanning electrochemical microscopy, spectroelec-trochemistry, complex impedance analysis) are used to test electrochemical cell. These tools allow the kinetic and mechanistic studies not readily available in nanoelectrochemistry. The research concentrated on improving the metallic catalyst, and also optimizing the interfacial contact and utilization. 

The generation of the cation can be monitored using an FTIR spectrometer (ATR method) equipped with a low-temperature flow cell attached to the outlet of the electrochemical microflow reactor. The absorption at 1814 cm , which is assigned as the C=0 vibration, increases with increase in the electric current. An interesting application of the cation flow method is continuous sequential combinatorial... 

Combinatorial electrochemical synthesis is defined as a method in which very large numbers of compounds are synthesized as ensembles (libraries) by combining a small number of building blocks together in all combinations defined by an electrochemical reaction. Combinatorial synthesis enables diversity oriented synthesis. If two building blocks (A and B) are combined by an electrochemical reaction and three different types of A and three different types of B are used, nine (3 x 3) different products (A-B) are produced. 100 types of each building block will yield 100 x 100 = 10,000 products. Use of such products as substrate for the next reaction leads to formation of a large number of compounds as chemical libraries. Combinatorial... 

Combinatorial Electrochemical Synthesis, Fig. 2 Parallel combinatorial synthesis based on the cation-pool method... 

Figure 12.2. (a) Schematic of synthesis routine for a multi-component catalyst gradient by gel-transfer method, (b) Optical image of concentration gradient of Pt /Ru /Rh in agarose gel [12]. (Reproduced by permission of ECS—The Electrochemical Society, from Jayaraman S, Hillier AC. Electrochemical synthesis and reactivity screening of a ternary composition gradient for combinatorial discovery of fuel cell catalysts.)... 

Besides SECM, other speetroseopie mefliods, such as scanning differential electrochemical mass spectrometry (SDEMS) and IR thermography, were also used as combinatorial screening methods for fuel cell electrocatalysis. The principle of SDEMS is to use mass spectrometry to locally measure dissolved gases and volatile liquid species near flie surfaces of catalyst arrays. IR thermography is based on reaction heat mapping. The heat results from the fuel cell electrochemical reactions on the catalyst arrays. Both methods can obtain reaction... 

The activity and performance of fuel cell electrocatalysts need to be evaluated in terms of electrochemieal parameters, including current density and electrode potential. Electrochemieal sereening methods have been identified as ideal direct approaches for combinatorial studies of fuel cell catalysts. Two types of electrochemical measurement systems have been developed for combinatorial screening of fuel cell catalysts the array half-cell system and the array single-cell system. 

A review of chemical sensors and arrays [6] focuses on conducting polymers as inherent receptors, the modification of conducting polymers with receptors, the use of conducting polymers as transducers as well as some applications in combinatorial and high-throughput assays. Fundamental aspects of redox-related conductivity and pH-sensitive conductivity are included, and applications to chemical- and enzyme-based biosensors are summarized based on analyte. A variety of detection methods (electrical, electrochemical, and optical) are surveyed. 

Fast screening of materials for their catalytic activity has gained popularity in the area of polymer electrolyte fuel cells. The method involves preparing a combinatorial library of various candidate catalysts of different composition and a quick evaluation of a key electrochemical parameter such as open-circuit potential or high-frequency impedance. This enables a quick screening of an array of materials to identify... 

---