Theoretical study of the mechanism of ruthenium catalyzed dehydrogenation of methanol-water mixture to H2 and CO2

•Detailed mechanism for the dehydrogenation of methanol-water mixture catalyzed by ruthenium complexes.•Direct hydride transfer route for the dehydrogenation of formic acid.•Solvent effect analysis for the geometric structures and relative free energies.

The mechanism for the dehydrogenation of methanol-water mixture catalyzed by [K (dme)2][RuH(trop2dad)] was studied by using the density functional theory method. We found that the imidazole ring acts as a “hydrogen reservoir” by taking the hydrogen atoms from methanol and water and releasing CO2 and three hydrogen molecules. A direct hydride transfer route for the dehydrogenation of formic acid was revealed. Furthermore, we also investigated the solvent effect in the reaction and found that the solvent have significant influence on the structures and relative energies.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide