Fig. 6. (a) Reaction scheme and (b) potential energy surface of M-ZSM-5–MeOH + MeOH (–OMe⁺via a rapid dehydration of MeOH₂⁺ over BAS) → M-ZSM-5 + DME (M = Ag, Zn and H), (c) transition state (TS) structure and charge value of Ag (qM) for R_MeOH and for TS, (d) electron location function (ELF) contour of (c).