Development of a new model reaction to characterize the weak reactivity of cationic zeolites

A new test in liquid phase using dodecen-1 isomerization as a model reaction was developed to characterize the weak reactivity of cationic zeolites.Thanks to it, the NaY weak activity can be characterized in conditions close to those of several industrial adsorption and separation processes (temperature around 150–200 °C and in liquid phase). Indeed, characterization by this model reaction of several NaHY prepared from NaY by exchanging some Na+ by protons and of NaY treated by NaOH allows us to attribute the NaY activity to residual Brönsted acid sites and even to estimate their number. Comparison of NaY before and after passivation of its external by TetraEthylOrthoSiloxane (TEOS) deposition enable us to propose that the residual active sites are mainly located at the external surface and/or in the porosity directly connected to this one.