The reaction mechanism of ethanol dehydration over SAPO-34 zeolite is investigated by using solid-state NMR spectroscopy.SAPO-34 zeolites with different Si contents are prepared and their acidities are characterized by NMR experiments.The higher content of stronger Brφnsted acid sites is correlated to the higher Si content.The adsorption of ethanol on the Brφnsted acid sites in SAPO-34 leads to the formation of frustrated Lewis pairs(FLPs).Surface ethoxy species is observed by the dehydration of the FLP sites at room temperature,which can be further converted into ethene products.The decomposing of diethyl ether over Brφnsted acid sites is responsible for the formation of ethoxy species at higher reaction temperatures.Triethyloxonium ions are formed in the reaction.A plausible reaction mechanism is proposed for the dehydration of ethanol over SAPO-34.