Abstract: Mass Spectrometry and quantum chemistry ab initio method have been used to study the reactivity of the methanol dehydration. It is shown that the methanol dimer and methanol cluster are the predominant species of methanol in gaseousness. So we believe that rather the methanol dimer is the original reactant of the methanol dehydration reaction to dimethyl ether than the mono-methanol. The structure and energy of the methanol dimer and the transition state for the dehydration reaction have been studied. It is discussed that the reaction pathway and factors influenced the reactivity of methanol dehydration to dimethyl ether theoretically.

Key words: Methanol condensation, Dehydration, Dimer, Mass spectrometry, Quantum chemistry method