Methanol dehydration over commercially available zeolites: Effect of hydrophobicity

Commercially available H-Y (Faujasite) and H-ZSM5 zeolites with various SiO2/Al2O3 ratio (from 5 to 280) were used as acid catalyst for vapour phase methanol dehydration in mild condition (T < 250 ̊C; P < 5 bar). All tested catalysts were giving very high selectivity while conversion was highly dependent on both acid content and surface hydrophobicity expressed as Weitkamp hydrophobicity index (HI index). For H-Y and H-ZSM5 zeolites, a correlation was found between catalysts productivity expressed in kg of DME per hour per concentration of acid sites and HI index. Such results could rise to the design of more efficient catalyst for gas-phase DME synthesis from methanol.