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The Process of Catalyst Selection
Published in Mike G. Scaros, Michael L. Prunier, Catalysis of Organic Reactions, 2017
Catalysts are designed with different metal locations for reactions taking place under different conditions of pressure and temperature. Hydrogenation reactions are generally first order with respect to hydrogen. As such, Standard catalysts with increased metal dispersions typically exhibit greater relative activity at high hydrogen pressures. The hydrogenation of benzoic acid to cyclohexanecarboxylic acid at 150°C, 100 atrn H2, is completed much more rapidly using a Standard 5% palladium on carbon catalyst than with an equivalent metal loading, lower metal dispersion Eggshell catalyst. Eggshell catalysts exhibit higher relative activity at low hydrogen pressures. An example of this for the low temperature and pressure hydrogenation of nitrobenzene to aniline is shown in Table 2. Hydrogenation of large molecules is generally carried out using Eggshell catalysts. For example, the hydrogenation of oleic acid at 30°C, 1 atm H2 is much more facile using an Eggshell 5% palladium on carbon catalyst than a Standard 5% palladium on carbon catalyst. Variation of metal location can also be used to alter catalyst selectivity.
Thermochemistry, Electrochemistry, and Solution Chemistry
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Chrysene Chrysene trans-Cinnamaldehyde trans-Cinnamic acid trans-Cinnamic acid Citric acid Clopyralid Clorophene Cocaine Codeine Colchicine Coronene Creatine o-Cresol m-Cresol p-Cresol Crufomate Cyanazine 2-Cyanoacetamide Cyanogen Cyanogen chloride Cyanoguanidine Cyanuric acid Cycloheptane Cycloheptanone Cycloheptanone 1,3,5-Cycloheptatriene Cycloheptene 1,4-Cyclohexadiene Cyclohexane Cyclohexane Cyclohexane Cyclohexanecarboxylic acid Cyclohexanol Cyclohexanol Cyclohexanol Cyclohexanone Cyclohexanone Cyclohexanone Cyclohexanone Cyclohexanone oxime Cyclohexene Cyclohexyl butanoate Cyclohexyl butanoate Cyclooctane 1,3-Cyclopentadiene Cyclopentane Cyclopentanol Cyclopentanol Cyclopentanol Cyclopentanone Cyclopentanone Cyclopentanone Cyclopentene Cyclopropane Cy uthrin Cygon Cyhalothrin Cypermethrin -Cystine
Review: Recent advances of one-dimensional coordination polymers as catalysts
Published in Journal of Coordination Chemistry, 2018
Edward Loukopoulos, George E. Kostakis
In 2016, another Cu(II) 1-D CP was reported by Paul and co-workers [58] toward oxidation of cyclohexane to the respective carboxylic acid. The authors employed a flexible terpyridine carboxylic acid derivative, 4-((4-([2,2′:6′,2″-terpyridin]-4′-yl)benzyl)oxy)benzoic acid (Htbba) to generate [Cu(tbba)(NO3)] (3), a 1-D coordination polymeric chain with five-coordinate Cu centers (Figure 3). Under the presence of the ionic liquid [BMPyr][NTf2] (where [BMPyr = 1-butyl-1-methylpyrrolidinium, NTf2 = bis(trifluoromethanesulfonyl)imide]) in aqueous medium, 3 can effectively catalyze the hydrocarboxylation of cyclohexane, producing the corresponding cyclohexanecarboxylic acid (Scheme 2) in 35.9% yield and in high selectivity. This one-pot conversion takes place under mild conditions and uses a low amount (0.8 mol%) of catalyst. Furthermore, the catalytic performance of 3 is maintained through four consecutive cycles after which a loss in activity is observed.