Density Functional Study of Methanol Synthesis from CO Hydrogenation on Cu-Based Catalysts

ABSTRACT The reaction mechanism of carbon monoxide (CO) hydrogenation to methanol has been carried out theoretically in this paper. The atomic configuration was analyzed by an unlimited B3LYP calculation method in density functional theory. The reaction model for CO hydrogenation to methanol was established by using Gaussian 09. The adsorption sites, bond angles, bond lengths, reaction intermediates, transition-state structures, adsorption energy, reaction-energy barriers, and reaction heat of CO hydrogenation to methanol with different amounts of copper-based catalysts were calculated. The calculations provided the elementary reaction of methanol in the synthesis, and the reaction potential-energy diagram for methanol synthesis was plotted. The optimum reaction path for CO hydrogenation to methanol was as follows: CO→HCO*→H2CO*→H3CO*→CH3OH. The rate-limiting step was the hydrogenation of the methoxy (H3CO) species with an activation barrier of 1.28 eV.