A DFT Study of Methanol Synthesis from CO2 Hydrogenation on the Pd(111) Surface

During the process of catalytic conversion of CO2 to valuable chemical products, Pd used as catalysts or modifiers shows promising effect on CO2 hydrogenation. The mechanism of methanol synthesis from the hydrogenation of CO2 on the Pd(111) surface was studied using density functional theory calculations in present work. On the Pd(111) surface, CO2 firstly hydrogenates to HCOO or COOH, each of which then reacts with the surface H atom to form HCOOH. Next, HCOOH dissociates to OH and HCO that will be consecutively hydrogenated to H2CO, H3CO and H3COH. CO is the main side product of CO2 hydrogenation on the Pd(111) surface with an activation barrier of 1.09 eV. The hydrogenation of HCO species with the surface H atom to form H2CO plays as the rate determining step for CO2 hydrogenation to methanol with the barrier of 0.91 eV. Our calculated results are favorable for the understanding of the mechanism of CO2 conversion on not only Pd-based catalysts but also Pd modified catalysts. The mechanism of methanol synthesis from the hydrogenation of CO2 on the Pd(111) surface was studied using density functional theory calculations.