Fluoride-treated H-ZSM-5 as a highly selective and stable catalyst for the production of propylene from methyl halides

► Fluoride-treated H-ZSM-5 is highly selective for C3H6 formation from CH3Cl or CH3Br. ► Fluoride treatment decreases acidity, inhibiting secondary reactions of light olefins. ► Fluoride treatment generates larger micropores in ZSM-5, increasing C3H6 selectivity. ► Conversion of methyl halide to light olefins proceeds via hydrocarbon pool mechanism. ► Acidity and porous structure determine the catalytic conversion of methyl halides.