Direct observation of hexamethylbenzenium radical cations generated during zeolite methanol-to-olefin catalysis: an ESR study

The generation of hexamethylbenzenium radical cations as the key reaction intermediate in chabazite-type molecular sieve acids (i.e., H-SAPO-34 and H-SSZ-13) during the methanol-to-olefin process has been directly evidenced by ESR spectroscopy.