A Kinetic Analysis to Delineate the Effect of Catalyst Pre-Treatment on the Performance of Pd/Al2O3 in Glycerol Oxidation

Oxidation state of the catalyst is important in determining the activity and selectivity of the catalyst in complex reaction networks. This effect is investigated here in the context of glycerol oxidation. An attempt is made to understand the effect of catalyst pre-treatment (oxidative and reductive) on Pd/Alumina for glycerol oxidation, and correlate the reaction performance with the oxidation state of Pd. Characterisation techniques such as XPS, TEM, CO pulse chemisorption have been used to understand the effect of pre-treatment on the oxidation state of the metal. The reduced catalyst was found to be more selective to C3 compounds than the oxidized catalyst. It is suggested that this difference in selectivity is due to differences in hydrogen peroxide formation over Pd and PdO phases, because of the role of peroxide in bringing about C-C scission. A novel procedure for parameter estimation based on reaction extents has been used to delineate the effect of pre-treatments on different reactions in the network. The results have been supported by systematic statistical analyses.