High-Throughput Screening of Catalysts and Reactions

Inspired by micro total analysis systems (pTASs), where sequential analytical operations can be automatically performed by computer control and which allow 

Despite the use of chromatographic separation methods as tools to investigate the course of reactions in detail, chromatographic data as well as reactions in the course of a chromatographic separation can also be used to perform physicochemical measurements. An example for this is the application of van 

Deemter s equation, which allows the determination of diffusion coefficients of analytes [26, 27]. It has to be noted that the original derivation of van Deemter s equation described heat and mass transport in a fixed catalyst bed during regeneration [28]  

In 1960, Bassett and Habgood [31] investigated the isomerization of cyclopropane to propylene catalyzed by the Linde molecular sieve 13x exchanged with Ni ions on a packed column. Cyclopropane was injected as a pulse onto the column, and the formation of the product was observed as an extremely broadened peak. Gil-Av and Herzberg-Minzly [32] investigated Diels-Alder 

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I 21 High-Throughput Screening of Catalysts and Reactions Reactant library... 

Figure 11.21 Results of high-throughput screening of catalysts in a 384-parallel single-bead reactor in a partial oxidation reaction, (a) Arrangement of inactive and total oxidation catalysts in the reactor, (b) screening results for the conversion of a hydrocarbon at 400°C, 1 mL/min per bead.

Trapp, O. Weher, S.K. Bauch, S. Hof-stadt, W. High-Throughput Screening of Catalysts by Combining Reaction and Analysis. Angew. Chem., Int. Ed 2007, 46,7307-7310. 

The best combination turned out to be L5 /A9 (ee = 90% at room temperature and 99% at —78 °C with benzaldehydes and ee = 92-99% with other aldehydes).87 Further improvements were reported later.89 Although only a few dozen reactions were monitored by a JASCO-CD-995 instrument, the CD-based assay is amenable to high-throughput screening of enantioselective catalysts. The chemistry itself lends itself ideally to combinatorial asymmetric metal catalysis, since the principle of asymmetric activation is turning out to be very powerful.89... 

Gas-solid catalytic techniques. Development of experimental techniques for high-throughput screening of gas-solid catalyzed reactions have received the most attention when compared to either gas-liquid catalyzed or polymerization reaction systems. The two key differences between the techniques for gas-solid systems are in the analytical methods used to extract one or more standard measures of catalyst performance, such as activity, conversion, or selectivity, and the catalyst form that is used. Table 1 gives a summary of the various techniques along with their distinguishing features. 

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