*2.2.1 Acid treatment on mordenite*

Ion exchange of zeolite type mordenite (HSZ-604HOA) was carried out with 1 M NH4Cl for 3 hours at 70 °C and calcined in a furnace at 550 °C for 5 hours as HM. Zeolite HM formed was refluxed in a solution of HNO3 (0.1 and 0.5) at a temperature of 70 °C for 2 hours, then washed with bi-distilled water until it was neutral, dried overnight at 110 °C, then calcined in a furnace 550 °C for 5 hours to form AM-0.1 and AM-0.5.
