MTO机理研究必威体育精装版进展-郑珩.pptVIP

MTO机理研究必威体育精装版进展 Outline History of MTO Catalysis Mechanisms Proposed for MTO Updates on MTO Research Methanol to Gasoline, Methanol to Olefin Methanol to Hydrocarbon—— A Route from Methane to Chemicals Early 1970s, Mobil, methanol isobutane to high-octane gasoline over HZSM-5 1985, Mobil ran MTG process commercially in New Zealand. 2006, DICP set up an MTO plant with an annual output of 40,000 t in Shanxi province. M Stocker, Micro. Meso. Materials., 1999, 29, 3-48 News released on Milestones in MTO Research Mechanisms of MTO (a) A pathway showing a carbenium ion alkylating dimethyl ether to form a carbonium ion. (b) One of several proposed carbene pathways. (c) An abbreviation of one of several free radical routes. S* is an unspecified surface radical species. (d) An alkoxy chain growth process occurring on a framework site. (e) One of the proposed mechanisms featuring CO, showing a role for transition-metal impurities. (f) An abbreviated oxonium-ylide route. J.F.Haw et al, Acc.Chem.Res., 2003, 36, 317-326 Early Proposed Carbon-pool Mechanism J.F.Haw et al, Acc.Chem.Res., 2003, 36, 317-326 Early proposals that have significantly shaped current thinking about the carbon pool mechanism in MTO catalysis. (a) Mole’s 1983 mechanism of methylbenzene side-chain alkylation. (b) An abbreviated account of Langner’s explanation for the dramatic effect of cyclohexanol and other co-feeds of reducing the kinetic induction period. (c) Kolboe’s early phenomenological hydrocarbon pool mechanism for MTO catalysis. (d) The paring reaction in highly abbreviated form. Mechanism proposed by J. F. Haw: Carbon-pool J.F.Haw et al, J.Am.Chem.Soc., 1998, 120, 2650-2651 13C MAS NMR spectra from pulse-quench in situ studies of MTG chemistry on zeolite HZSM-5 at 643 K with He carrier gas flow. Reaction times from 200 ms to 16 s. 13C NMR signals of methanol (50 ppm), dimethyl ether (59 ppm), and cations similar to intermediate (249, 146 and 46 ppm) are indicated. Signals in the