Catalytic dehydrogenation of the liquid organic hydrogen carrier octahydroindole on Pt (111) surface: Ab initio insights from density functional theory calculations

Ab initio calculations based on dispersion-corrected density functional theory were used to gain insight into the adsorption properties of reactants and products involved in the catalytic dehydrogenation of octahydroindole on a Pt (1 1 1) surface. Octahydroindole is the hydrogen-rich form of a liquid organic hydrogen carrier (LOHC); indole is the hydrogen-lean form of the LOHC, and indoline is a possible dehydrogenation intermediate of the LOHC. The adsorption of octahydroindole, indoline, and indole on a Pt (1 1 1) surface were found to be energetically favored. Dehydrogenation of octahydroindole proceeded by the systematic removal of H-2 molecules along different dehydrogenation reaction paths. Investigation of these paths revealed that dehydrogenation of octahydroindole to indole can take place with or without indoline as intermediate. This observation was consistent with experimental results.