CO2 hydrogenation to formic acid over platinum cluster doped defective graphene: A DFT study

The hydrogenation of CO2 to formic acid is an important reaction in environmental catalysis, which can both alleviate the greenhouse effect and produce useful chemicals. Platinum element catalysts need to be investigated to realize large-scale development due to the expensive and scarce features. In this work, CO2 hydrogenation to formic acid over Pt4 cluster doped single-vacancy graphene was investigated using density functional theory. Catalyst configuration was optimized to perform corresponding gas adsorption and reduction reaction. Four reaction pathways were explored according to the reaction mechanism of Langmuir-Hinshelwood (L-H), Eley-Rideal (E-R) and termolecular Eley-Rideal (TER). Kinetic analysis was used to evaluate the reaction rate of different processes under the given temperature range, and the potential effect of CO molecule was also considered to better understand the feasibility. Results showed that Pt4/SV was a stable and high activity catalyst. The minimum activation energy among different pathways was 0.56 eV and TER could be the dominant reaction mechanism of CO2 hydrogenation. This work not only provides a promising catalyst but also gives a more deep understanding of CO2 reduction technology and the future applicability of platinum metal catalysts.