F. Salehirad et Mw. Anderson, NMR-STUDIES OF METHANOL-TO-HYDROCARBON CHEMISTRY - PART 1 - PRIMARY PRODUCTS AND MECHANISTIC CONSIDERATIONS USING A WIDE-PORE CATALYST, Journal of the Chemical Society. Faraday transactions (Print), 94(13), 1998, pp. 1911-1918
Citations number
31
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
The conversion reactions of methanol over H-ZSM-12 and H-Beta zeolites
using a static microreactor and a continuous flow system are compared
and contrasted. The surface of both zeolites is methylated prior to t
he conversion of methanol to hydrocarbon (i.e. less than or equal to 4
93 K). Methane and ethene, which are observed in the very early stages
of conversion over the zeolites, are viewed as primary hydrocarbons.
The high selectivity for isobutane is considered to be related to the
low reactivity of active sites (in H-Beta) to secondary conversion suc
h as ethene oligomerisation and to the distribution of acid sites and
pore geometry (in H-ZSM-12). The reaction of methanol, in the presence
of hydrogen and oxygen, over H-Beta provides experimental evidence ag
ainst the involvement of radical species in the conversion reaction. T
he high selectivity to isobutane is also found for the conversion of i
sopropanol over premethylated Beta. This is discussed in terms of a po
ssible mechanism.