Zeolite-Catalyzed Hydrocarbon Formation from Methanol: Density Functional Simulations

Abstract

Abstract:We report detailed density functional theory (DFT) calculations of important mechanisms in the methanol to gasoline (MTG) process in a zeolite catalyst. Various reaction paths and energy barriers involving C-O bond cleavage and the first C-C bond formation are investigated in detail using all-electron periodic supercell calculations and recently developed geometry optimization and transition state search algorithms. We have further investigated the formation of ethanol and have identified a different mechanism than previously reported [1], a reaction where water does not play any visible role. Contrary to recent cluster calculations, we were not able to find a stable surface ylide structure.However, a stable ylide structure built into the zeolite framework was found to be possible, albeit a very high reaction barrier.

A DFT study of adsorption hydrogen on the Li-FAU zeolite

“…The DMol 3 program uses numerical functions that are far more complete than the traditional Gaussian functions. Moreover, this basis set is known to produce a small BSSE [27,28]. Considering both the size of the model and the level of calculation method, we are convinced that the conclusions that will be drawn in the following should be quite reliable.…”

Umwandlung von Methanol in Kohlenwasserstoffe: Wie Zeolith‐Hohlräume und Porengröße die Produktselektivität bestimmen

“…In vielen dieser Mechanismen wird eine C-C-Bindung durch Methylierung von C 1 -Fragmenten oder DME gebildet. [79,97,98] In diesem Fall ist in Gleichung (3) k 1 klein und P 0 = 0. Eine anderer vorgeschlagener Reaktionsweg zur Bildung einer C-C-Bindung ist die Reaktion von Methan und protoniertem Formaldehyd.…”

Methanol coupling in the zeolite chabazite studied via Car–Parrinello molecular dynamics

“…These three studies were all performed using small cluster models and static calculations. In the fourth study, Govind et al [5] performed static calculations on *Author for correspondence. e-mail: trout@mit.edu a periodic model of two methanol molecules in ferrierite, and again proposed the reaction of a surface methoxy species with methanol or dimethyl ether to form ethanol or methyl-ethyl-ether; water does not play any visible role in their mechanism.…”