Seite - 119 - in Advanced Chemical Kinetics

CA0 is the initial concentrationofA, k is the rateconstantwithunitsasmolL�1min�1and t is time inminutes, andthat, k isdependenton temperature, k¼A:e� EA RT (2) where k is the rateconstantwithunitsasmolL�1h�1 A is thepre-exponential factor, specific to this reaction EA is theactivationenergyof the reaction, R is thegasconstant8.314 Jmol�1K�1 and T is the temperature inKelvin. Figure4 shows theplotofglycerol conversionasa functionof time forexperiments thatwere carriedoutat 60and90�C.Usually, k is regardedas the rate coefficient of theoverall reaction, which is somemeasure of catalyst activity, but in essence, as shownbyEqs. (1) and (2), k is temperature-dependent, aswell as concentration-dependent, usuallydependent on the initial concentrationof the reactant. Figure3. Initial rateasa functionofcatalystmass forglyceroloxidationover0.9-wt%Au/γ-Al2O3 (106–150mμ):1000rpm, NaOH/glycerol=2:1,at60�C,under8.5-barO2pressure. Oxidation of Glycerol to Lactic Acid by Gold on Acidified Alumina: A Kinetic and DFT Case Study http://dx.doi.org/10.5772/intechopen.70485 119