Temperature, 2-propanol decomposition oxide

Temperature-Programmed Decomposition of 2-Propanol on the Zinc-Polar, Nonpolar, and Oxygen-Polar Surfaces of Zinc Oxide... 

The dehydrogenation reaction produces acetone and hydrogen, and is dominant over basic oxides ( ) The dehydration reaction produces propene and water, and is dominant over acidic oxides. It would be interesting to see if the competition between these two pathways depend on the exposed crystal planes of ZnO. We report here the results of such an investigation. 2-Propanol was decomposed on ZnO single crystal surfaces by the temperature programmed decomposition technique. To assist the interpretation of data, the temperature programmed desorption of propene and acetone were also studied. 

Let us compare the ratio of radicals in oxidized 2-propanol and cyclohexanol at different temperatures when oxidation occurs with long chains and chain initiation and termination do not influence the stationary state concentration of radicals. The values of the rate constants of the reactions of peroxyl radicals (kp) with alcohol and decomposition of the alkylhydroxy-peroxyl radical (k ) are taken from Table 7.4 and Table 7.5. 

To improve process economics, further work is needed to improve catalyst lifetimes. A more stable system employed a noble metal-loaded potassium L-zeolite catalyst for the condensation of ethanol with methanol to produce a 1-propanol and 2-methyl-l-propanol (US patent no. 5,300,695) (18). However, yields were small compared with the large amounts of CO and C02 produced from the methanol. More recently, Exxon patented a noble metal-loaded alkali metal-doped mixed metal (Zr, Mn, Zn) oxide (US patent nos. 6,034,141 and 5,811,602) (19,20). The catalyst was used in a syngas atmosphere. As with other catalysts, the higher temperatures resulted in decomposition of methanol. Changes in catalyst composition were noted at higher temperatures, but the stability of the catalyst was not discussed. Recently, compositions including Ni, Rh, Ru, and Cu were investigated (21,22). 

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