Nanochemistry and biotechnology

Mechanism of methanol interaction with defects 
on graphene-like materials: quantum chemical study
Karpenko O.S.1, Bychko I.B.2, Strizhak P.E.2
1 Chuiko Institute of Surface Chemistry of the NAS of Ukraine, General Naumov Str., 17, Kyiv-03164, Ukraine.
E-mail: karpenkooksana@ukr.net
2 L.V. Pisarzhevsky Institute of Physical Chemistry of the NAS of Ukraine,
Prospect Nauki, 31, Kyiv-03028, Ukraine.

Methanol conversion to dimethyl ether or formaldehyde are large-scale industrial processes. According to this, huge attention focused on finding ways to reduce the cost of relevant processes. Developing of the carbon catalysts for presented processes is one of the main route to reduce the cost of the methanol conversion. There are presented experimental works where carbon materials, particularly, carbon nanotubes [1], activated carbon, graphene materials are used as catalysts. However, reaction mechanisms of methanol conversion interaction in carbon materials is still under discussion.
This report presents the results of quantum chemical calculations by the method of density functional theory (DFT, B3LYP/6-31G+(d,p) with the involvement of Grimme dispersion correction) of the main elementary stages of methanol dehydration to dimethyl ether and dehydrogenation to formaldehyde on graphene-like materials (GLM). As models of GLM was used the polyaromatic molecule C96H24 (hydrogenated graphene) and its derivatives. Where considered two cases of methanol interaction: with point defects on C96H24 (single vacancy) and with C96H24 functionalized by oxygen functional groups like hydroxyl (–OH) and carboxyl (–COOH). The systems were tested under different conditions of multiplicity. Computed reaction profiles of the reactions were investigated. The role of the water molecule in the reaction of methanol dehydration to dimethyl ether was studied. Obtained results shows that active sites in dehydration reaction are hydroxyl and carboxyl group and in dehydrogenation reaction – single vacancy.
This work was supported by the National Research Foundation of Ukraine (grant 2020.02/0050).

1.	Yan P., Zhang X., Herold F., Li F., Dai X., Cao T., Etzold B. J. M., Qi W. Methanol oxidative dehydrogenation and dehydration on carbon nanotubes: active sites and basic reaction kinetics // Catal Sci Technol.-2020.-10, N 15.-P. 4952-4959.