The first transition metal series TM–PP monolayer catalysts exhibit excellent catalytic performance during the process of electroreduction of CO2. The products have 2e− CO (Sc, Mn and Ni), HCOOH (Cr, Fe, Co, Cu and Zn), 8e− CH4 (Ti and V), and the overpotential of the reaction can be as low as 0.127 V.

Eight novel two-dimensional TM–TCNQ (TM = V–Zn) monolayers as highly efficient and selective electrocatalysts for CO2 reduction have been systematically studied and the underlying detailed reaction mechanisms have been revealed.

Electrochemical CO 2 reduction to value-added fuels and chemicals provides a "clean" and efficient way to mitigate energy shortages and to lower the global carbon footprint if one could find highly stable, efficient, selective, and low-cost electrocatalysts. However, this remains a huge challenge. In this work, the catalytic performance of transition metal−phthalocyanine (TM−Pc) monolayers as single-atom catalysts for the electroreduction of CO 2 was systematically investigated by spin-polarized density functional theory (DFT) calculations. Our results show that the bonding of single metal atoms with Pc can be large enough for the individual atoms to be uniformly dispersed and anchored in a modified 2D TM−Pc monolayer. Considering the competing hydrogen evolution reaction, TM−Pc has a good hydrogen evolution inhibition. The main CRR reduction products of Sc−Pc, Ti−Pc, V−Pc, and Fe−Pc monolayers are CH 4 . For Cr−Pc, Mn−Pc, and Zn−Pc monolayers, HCOOH is dominant, while for Co-Pc, HCHO is predicted. Except for the Sc−Pc, Ti−Pc, and V−Pc monolayers by (with too large overpotentials, exceeding 1 V), the reduction overpotential of other TM-Pc catalysts are in the range of 0.017−0.819 V, among them Mn−Pc has the lowest overpotential (0.017 V) and Fe−Pc has the highest overpotential (0.819 V). These were all lower than the overpotentials of well-studied copper which has the best catalytic performance. Therefore, our work may open up new avenues for the development of highly efficient catalytic materials for CO 2 reduction.

These new TM–Bβ12 monolayers will display excellent catalytic performance for electroreduction of CO2. Primary reduction product of Sc is CO (overpotential 0.45 V). Primary product Ti–Zn is CH4, and Fe–Bβ12 has 0.45 V overpotential.

Organometallic nanosheets are a versatile platform for design of efficient electrocatalyst materials due to their high surface area and uniform dispersion of metal active sites. In this paper, we systematically investigate the electrocatalytic performance of the first transition metal series TM3–C12S12 monolayers on CO2 using spin‐polarized density functional theory. The calculations show that TM3–C12S12 exhibits excellent catalytic activity and selectivity in the catalytic reduction in CO2. The main reduction products of Sc, Ti, and Cr are CH4. V, Mn, Fe and Zn mainly produce HCOOH, and Co produces HCHO, while CO is the main product for Ni and Cu. For Sc, Ti, and Cr, the overpotentials are >0.7 V, while for V, Mn, Fe, Co, Ni, Cu, Zn, the overpotentials are very low and range from 0.27 to 0.47 V. Therefore, our results indicate that many of the TM3–C12S12 monolayers are expected to be excellent and efficient CO2 reduction catalysts.