Electrochemical CO₂ Reduction Reaction on M@Cu(211) Bimetallic Single-Atom Surface Alloys: Mechanism, Kinetics, and Catalyst Screening

Abstract

Copper is a well-known metal for catalyzing the electrochemical CO 2 reduction reaction (CO 2 RR) toward valuable hydrocarbons and alcohols. Here, using a combined density functional theory and microkinetic modeling approach, we systematically investigated 11 bimetallic M@Cu(211) single-atom stepped surface alloys for their CO 2 RR activity. It is revealed that the stepped M edge is most likely to be the active site for CO 2 RR. The primary reaction pathway is identified as *COOH → *CO → *CHO with the potential-determining step of *CO + H + + e − → *CHO, leading to either CH 4 or CH 3 OH formation at more negative potential. Especially, Ru@Cu(211) and Fe@Cu(211) are both predicted to be most efficient in promoting CO 2 RR toward CH 4 owing to their breaking of the coupled scaling relations of key intermediates' binding at the active site. Furthermore, the binding strength of *CO and *OH can be used as a good descriptor for differentiating various M@ Cu(211) for CO 2 RR activity and selectivity, and specifically, the moderate oxophilic and carbophilic elements of M are preferred. Our study highlights the utmost importance of breaking the linear scaling relations of key intermediates' binding at the active site for boosting CO 2 RR performance.

Promoting CO2 methanation via ligand-stabilized metal oxide clusters as hydrogen-donating motifs

“…These motifs reduce H 2 O to produce *H, which will hydrogenate *CO on neighbouring Cu atoms to *CHO. We also compared the *CO hydrogenate energies on pure Cu via the H 2 O-assisting Heyrovsky mechanism vs. the *H transfer mechanism 30 , 31 (0.63 vs. 0.43 eV, Supplementary Fig. 1 ): the *H transfer mechanism is more likely from a thermodynamic analysis.…”

Dioxygen Binding to all 3d, 4d, and 5d Transition Metals from Coupled‐Cluster Theory

“…The differences between these two reaction energies are of particular importance, as discussed further below. The reaction energies are also compared to the oxophilicity of each metal derived from a normalized scale of relative experimental M−O and M−S binding strengths, which explains many trends in activity of larger systems well . As seen, the two reaction energies generally correlate, but there is an important deviation in the middle d‐block that metals bind O 2 to a similar extent, whereas the M−O bond strength follows the double hump structure through the d‐block due to d‐orbital net‐bonding as is typical and very similar to e. g. hydration free energies and cohesion energies .…”

Atomically dispersed Cu and Fe on N-doped carbon materials for CO2electroreduction: insight into the curvature effect on activity and selectivity

“…As shown in Table S1, † the free energy of gaseous species is calculated at the standard atmospheric pressure of 1 bar, while the free energy of liquid species is obtained by using the corresponding vapor fugacity (f), based on the ideal gas-model calculations. According to previous studies, 47 the chemical potential corrections of À0.09, À0.22, and À0.07 eV for H 2 O (aq), HCOOH (aq), and CH 3 OH (aq), respectively, have been considered in determination of the Gibbs free energy change.…”