Modification Strategy of ZSM-5 Zeolite for Enhancing p-Xylene Selectivity in Toluene Disproportionation

In this study, modified zeolite was used to improve p-xylene selectivity in toluene dis-proportionation process. ZSM-5 zeolite was modified by introducing the phosphorus/Germanium loading and vacuum UV treatment from He+O2 microwave plasma treatment. Results showed that the ZSM-5 zeolite impregnated with Germanium and phosphorus have high p-xylene selectivity (up to 33 %). A sharp decrease in the acidity properties was achieved after phosphorus loading. By Germanium loading, selectivity increased but conversion did not change much. Also, the highest p-xylene selectivity (47 %) was obtained by P/Ge ZSM-5 with VUV treatment at the highest WHSV of 85 h-1.