The reaction of methanol with CO2 to obtain dimethoxymethane (DMM) at 150 degrees C and initial pressure of 3.0 MPa CO2 was realized in the presence of basic functionalized ionic liquid BmimOH. Although the conversion of methanol was low (2.4%), CO2 as a soft oxidant was firstly introduced for selective oxidation of methanol into DMM. The effect of the functionalized group composed of ionic liquids on the reactivity and selectivity was explored and the activation and reaction mechanism of the ionic liquid for methanol and CO2 was proposed. In addition, the reaction thermodynamics of methanol and CO2 was discussed by calculating the thermodynamic functions of the reaction in order to explore the direction and limitation of the reaction. (C) 2016 Elsevier B.V. All rights reserved.