Modulating the Asymmetric Atomic Interface of Copper Single Atoms for Efficient CO₂ Electroreduction

Abstract

Cu single-atom catalysts (Cu SACs) have been considered as promising catalysts for efficient electrocatalytic CO 2 reduction reactions (ECRRs). However, the reports on Cu SACs with an asymmetric atomic interface to obtain CO are few. Herein, we rationally designed two Cu SACs with different asymmetric atomic interfaces to explore their catalytic performance. The catalyst of CuN 3 O/C delivers high ECRR selectivity with an FE CO value of above 90% in a wide potential window from −0.5 to −0.9 V vs RHE (in particular, 96% at −0.8 V), while CuCO 3 /C delivers poor selectivity for CO production with a maximum FE CO value of only 20.0% at −0.5 V vs RHE. Besides, CuN 3 O/C exhibited a large turnover frequency (TOF) up to 2782.6 h −1 at −0.9 V vs RHE, which is much better than the maximum 4.8 h −1 of CuCO 3 /C. Density functional theory (DFT) results demonstrate that the CuN 3 O site needs a lower Gibbs free energy than CuCO 3 in the rate-determining step of CO desorption, leading to the outstanding performance of CuN 3 O/C on the process of ECRR-to-CO. This work provides an efficient strategy to improve the selectivity and activity of the ECRR via regulating asymmetric atomic interfaces of SACs by adjusting the coordination atoms.

Insight on Atomically Dispersed Cu Catalysts for Electrochemical CO2 Reduction

“…93 For example, Cu−N 2 sites with unsaturated coordination environment exhibited short bond length, which could accelerate the transfer of electrons from active sites to CO 2 *. 94 And Song et al 95 reported an adjusting strategy of asymmetric atomic interface (Cu−O/C and Cu−O/ N coordination) of Cu SACs (Figure 7a). The rate-determining step (CO desorption) occurred more easily at CuN 3 O sites than at CuCO 3 sites, resulting in CuN 3 O sites exhibiting a large turnover frequency (TOF) up to 2782.6 h −1 and higher selectivity (Figure 7b).…”

“…(b) TOF values of CuNO 3 /C and CuCO 3 /C for CO production based on the loading amount of Cu atoms at different applied potentials. Reprinted with permission from ref . Copyright 2023 American Chemical Society.…”

Experimentally revealed and theoretically certified synergistic electronic interaction of V-doped CoS for facilitating the oxygen evolution reaction

“…The DG values of different steps of OH*, O*, and OOH* were selected to elucidate the electrocatalytic activity mechanism. 39,40 The theoretical initial potentials for the OER on CoS, MoCoS and VCoS were calculated using eqn (S1) (ESI †). The rate-determining step (RDS) is the step with the largest DG n value for the fourelectron process.…”

Size effects of supported Cu-based catalysts for the electrocatalytic CO2 reduction reaction

“…In addition, the CuN 3 O/ C reported by Song et al demonstrated good performance at −0.8 V with a FEco of 96%. 52 Researcher Cong Liu reported the preparation of single-atom carbon-loaded Cu catalysts using a Cu-Li hybrid approach (Fig. 5e).…”

“…In addition, the CuN 3 O/C reported by Song et al demonstrated good performance at −0.8 V with a FEco of 96%. 52…”