Water enhanced mechanism for CO2 – Methanol conversion

[Display omitted] •CO2–CH3OH conversion in aqueous phase has been envisaged: (CO2 + 3H2 + H2O + H3O+).•The reaction has been investigated by using the high level W1U composite method.•Hydrogenations are the least favourable steps in the reaction.•The energy storage efficiency of the studied mechanism is 27.1%.•Catalysts can be designed to decrease the energy barrier and increase efficiency. Carbon dioxide can be converted into fine chemicals such as methanol and thus, the produced renewable energy can be stored in chemical bonds through reductions. To achieve this, a water enhanced mechanism of CO2 hydrogenation leading to methanol has been designed by applying 1:3 (CO2 + 3H2) extended with a water molecule and a hydronium. The thermodynamic properties of the intermediate species and transition states have been calculated by using the W1U composite method. The energy efficiency of the studied mechanism is 27.1%. By understanding the mechanism, special purpose catalysts can be designed to accelerate carbon dioxide conversion.