Mode of zeolite catalysts deactivation during chlorinated VOCs oxidation Original Research Article

The catalytic oxidation of tetrachloroethylene (PCE), chosen as model for chlorinated hydrocarbons, was investigated over Pt/HY, Pt/NaY and Pt/NaX under humid conditions at a space velocity of 15,300 h−1. PCE is selectively transformed into carbon dioxide (CO2) and hydrochloric acid (HCl) over all catalysts studied in this work. 1.2%Pt/HY exhibits the highest activity with the complete conversion of PCE at 500 °C and undergoes no significant deactivation after 4 h of reaction. It was also highlighted in this work, that water vapour plays a preponderant role for PCE transformation and limits catalyst deactivation. On the other hand, platinum-exchanged sodic faujasites (Pt/NaFAU) are also active in PCE transformation but it appeared that 1%Pt/NaX underwent a high and rapid deactivation by the formation of sodium chloride (NaCl) clusters.