Synthesis and decomposition of trimethyloxonium ZSM-5, a purported intermediate in methanol conversion into gasoline

Abstract

Trimethyloxonium cation (TMO) in zeolite ZSM-5 reacts principally as a surface methylating agent, similar to TMO salt decomposition with other weak conjugate bases (e.g. BF₄, arenesulphonates); recent reports of C₂ product formation from dimethyloxonium methylide generated by heating TMO salts with strong, poorly nucleophilic bases such as NaH and Li(2,2,6,6-tetramethylpiperidyl) do not accurately model the actual behaviour of this cation in ZSM-5.