Deactivation handling in a high-throughput kinetic study of o-xylene hydrogenation
Résumé
The objective of the study is to develop an HT methodology to enable kinetic modeling of diverse catalysts. The reaction of o-xylene hydrogenation is selected as a probe reaction to evaluate the ‘‘metallic'' features of a library of about 80 diverse bimetallic catalysts. A major issue to overcome is deactivation phenomena which are catalyst dependent and which cannot a priori be predicted. A prerequisite is therefore to handle correctly deactivation processes for accessing intrinsic kinetic parameters. For this purpose, an adapted screening strategy is developed, using a proprietary 16 channels multi-tubular reactor which enables to test catalysts at the same time-on-stream. Original data treatment procedures are implemented in order to correct observed data from deactivation phenomena for the calculation of kinetic parameters. Effects ofmetal nature, dopants and supports on deactivation rate are analyzed using a statistical approach, and a tentative classification of deactivation processes based on coke analyses performed on aged materials is provided.