Kinetic studies of zeolite-catalyzed methylation reactions. Part 2. Co-reaction of [12C]propene or [12C]n-butene and [13C]methanol

Methylation of benzene by methanol: Single-site kinetics over H-ZSM-5 and H-beta zeolite catalysts

“…As is clearly seen in Figure 5, the higher methylation activity of H-ZSM-5 relative to H-beta is maintained over an extended range of conditions. In agreement with previous reports for the methylation of alkenes [17,18,22], the reaction orders are one for benzene and very close to zero for methanol, resulting in the following empirical rate law:…”

“…Notably, this is the same H-ZSM-5 catalyst as employed in our previous studies of the methylation of alkenes [17,18]. These catalysts were selected due to similarities with respect to crystal size and acid site density.…”

“…A description of the experimental setup has been given in a previous paper [17,18]. Briefly, all kinetic measurements were carried out at atmospheric total pressure using a 3 mm inner diameter fixed bed reactor.…”

“…In every catalytic cycle proposed to date to explain olefin formation, methylations were found to be key reaction steps [14][15][16]. For these reasons methylations have received a lot of attention in several recent studies, in which they were examined from both an experimental and a theoretical angle [17][18][19][20][21].…”

“…Obtaining detailed information about any individual reaction is therefore non-trivial from an experimental point of view, as the rate of a single reaction is not easily monitored. Svelle et al first accomplished this for specific methylation reactions of alkenes by methanol on zeolite H-ZSM-5 [17,18], and more recently Hill et al performed an experimental study on the kinetics of alkene methylation by dimethyl ether on zeolites H-ZSM-5, H-beta, H-ferrierite, and H-mordenite [22], but in general experimental kinetic measurements of isolated zeolite-catalyzed reactions are rarely reported.…”