ISSN 00231584, Kinetics and Catalysis, 2013, Vol. 54, No. 2, pp. 157–167. © Pleiades Publishing, Ltd., 2013. Original Russian Text © D.E. Zavelev, G.M. Zhidomirov, R.A. Kozlovskii, 2013, published in Kinetika i Kataliz, 2013, Vol. 54, No. 2, pp. 166–176. Quantum Chemical Study of the Mechanism of the Catalytic Oxyethylation of Ethylene Glycol on PhosphorusDoped Titanium Dioxide: The Role of the Surface Phosphoryl and Hydroxyl Groups of the Catalyst D. E. Zaveleva,*, G. M. Zhidomirovb,c, and R. A. Kozlovskiid a Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, 119991 Russia b Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090 Russia c Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 119991 Russia d Mendeleev University of Chemical Technology of Russia, Moscow, 125047 Russia *email:
[email protected] Received June 25, 2012 Abstract—DFT calculations of the oxyethylation pathways of monoethylene glycol (MEG) and diethylene glycol (DEG) were performed on a model fragment of phosphorusdoped titanium dioxide (anatase). It was shown that the surface hydroxyl group of titanium dioxide, whose proton initiates C–O bond cleavage in the ethylene oxide molecule, plays the key role in the activation of the molecule. At the same time, the phospho ryl group –P(OH)2O activates the reactant molecule R (MEG, DEG, etc.) and carries out the synchronous proton transfer from R to the hydroxyl oxygen atom of titanium dioxide, thus restoring the catalyst structure and closing the catalytic cycle. This restructuring occurs synchronously in one step. The substitution of the catalyst hydroxyl groups by alkoxyl groups can influence oxyethylation occurring via the bimolecular nucleo philic substitution mechanism and can poison the catalyst in some cases.