Discovery of single-atom alloy catalysts for CO2-to-methanol reaction by density functional theory calculations

The transformations of CO2 molecules into valuable products are of increasing interest due to the negative impact of anthropogenic CO2 emissions on global warming. The CO2-to-methanol hydrogenation is an economically profitable reaction of carbon fixation, but it still steps away from widespread industrialization because of the lack of efficient and selective catalysts. Recently, single-atom alloy (SAA) catalysts have been developed to work remarkably in CO2 hydrogenation reactions. Doping isolated single atoms into metallic catalyst can dramatically alter the catalytic performance of the host. We have performed a screening discovery on Ru and 6 RuX (X = Fe, Co, Ni, Cu, Ir and Pt) SAAs using density functional theory (DFT) computations. We considered 13 possible elementary reactions in 4 possible reaction pathways on Ru and all RuX surfaces. In the computed mechanisms, we found that the formation of *H2COOH and *HCOO intermediates plays a critical role in determining catalysts' activities. Doping Co and Pt isolated single atoms into Ru surface can thermodynamically and kinetically facilitate these intermediates formation processes, eventually promoting the production of methanol. The combination of weak binding and enhanced charge redistribution on RuCo and RuPt surfaces give them improved catalytic activities over pure Ru. This work will ultimately facilitate the discovery and development of SAAs for CO2 to methanol, serving as guidance to experiments and theoreticians alike.

Automated summary

The transformation of CO2 into valuable products is an important field of research due to its impact on global warming. Single-atom alloy (SAA) catalysts have shown promising results in CO2 hydrogenation reactions. In this study, the authors used density functional theory (DFT) computations to screen Ru and 6 RuX (X = Fe, Co, Ni, Cu, Ir and Pt) SAAs as potential catalysts. The formation of specific intermediates was found to play a critical role in determining the catalysts' activities, and the doping of Co and Pt single atoms into Ru surface was found to enhance the production of methanol.