A Tandem Strategy for Enhancing Electrochemical CO₂ Reduction Activity of Single‐Atom Cu‐S₁N₃ Catalysts via Integration with Cu Nanoclusters

Abstract

We developed a tandem electrocatalyst for CO 2 -to-CO conversion comprising the single Cu site co-coordinated with N and S anchored carbon matrix (Cu-S 1 N 3 ) and atomically dispersed Cu clusters (Cu x ), denoted as Cu-S 1 N 3 /Cu x . The as-prepared Cu-S 1 N 3 /Cu x composite presents a 100 % Faradaic efficiency towards CO generation (FE CO ) at À0.65 V vs. RHE and high FE CO over 90 % from À0.55 to À0.75 V, outperforming the analogues with Cu-N 4 (FE CO only 54 % at À0.7 V) and Cu-S 1 N 3 (FE CO 70 % at À0.7 V) configurations. The unsymmetrical Cu-S 1 N 3 atomic interface in the carbon basal plane possesses an optimized binding energy for the key intermediate *COOH compared with Cu-N 4 site. At the same time, the adjacent Cu x effectively promotes the protonation of *CO 2 À by accelerating water dissociation and offering *H to the Cu-S 1 N 3 active sites. This work provides a tandem strategy for facilitating proton-coupled electron transfer over the atomic-level catalytic sites.Electrochemical reduction CO 2 to value-added fuels using renewable electricity is one of appealing CO 2 utilization strategies for management of the global carbon balance. [1] Recent technoeconomic analysis shows that the reduction of CO 2 to CO or formic acid through two-electron transfer processes is the most economical approach for CO 2 conversion, owing to their high added value per KJ of electrical energy input. [2] As a typical product, CO, especially with high purity, is very attractive, because it can be readily used as an important feed-stock for a couple of chemical engineering processes such as Fischer-Tropsch synthesis. [3] Thus, efficient CO 2 -to-CO conversion catalysts with adequate activity and selectivity are highly desired.

Anchoring Ionic Liquid in Copper Electrocatalyst for Improving CO2 Conversion to Ethylene

“…The lower free energies demonstrate that the IL@Cu catalyst facilitates the process of *CO dimerization and *OCCO formation. [42] These calculated results reveal that the free energies of *CO dimerization and *OCCO formation in CO 2 RR are decreased through regulating the coordination environment of Cu by BmimNO 3 , thus enhancing the electrocatalytic CO 2 RR performance of the IL@Cu catalyst.…”

Anchoring Ionic Liquid in Copper Electrocatalyst for Improving CO2 Conversion to Ethylene

“…Over the IL@Cu catalyst, the free energies of 2*CO and *OCCO formations were calculated to be 0.80 and 2.10 eV, while those for pure Cu catalyst are 1.02 and 2.45 eV, respectively (Figure 5f). The lower free energies demonstrate that the IL@Cu catalyst facilitates the process of *CO dimerization and *OCCO formation [42] . These calculated results reveal that the free energies of *CO dimerization and *OCCO formation in CO 2 RR are decreased through regulating the coordination environment of Cu by BmimNO 3 , thus enhancing the electrocatalytic CO 2 RR performance of the IL@Cu catalyst.…”

Optimized hot electron injection from Cu nanoparticles to S-doped C3N4by the formed S–Cu bonds for an enhanced photocatalytic performance

“…For the n-type contact of metal and semiconductor, the Schottky barrier height ( Φ e ) can be expressed by eqn (2): 20 Φ e = E CBM − E F where E CBM and E F are the bottom of the conduction band (CB) of CN in CN– or SCN–Cu and the Fermi level of the system, respectively. The Gibbs free energy change (Δ G ) of the hydrogen evolution reaction (HER) steps including H 2 O dissociation or H adsorption of CN-Cu and SCN–Cu was calculated by eqn (3): 21,22 Δ G = E DFT + E ZPE − T Δ S where E DFT , E ZPE and Δ S are the optimized adsorption energy of CN-Cu or SCN–Cu directly from the DFT calculations, zero-point energy correction and their entropy change, respectively, and the temperature T is set to 298.15 K.…”