In Situ Reconstruction of Cu–N Coordinated MOFs to Generate Dispersive Cu/Cu₂O Nanoclusters for Selective Electroreduction of CO₂to C₂H₄

Abstract

Electrochemical reduction of CO2 to obtain high-value-added feedstocks is a promising strategy to alleviate the energy crisis. Cu-based catalysts generate multi-carbon products with high activity in the CO2 reduction reaction (CO2RR), although great challenges remain in the selectivity and stability of Cu-based catalysts. Here, highly active Cu/Cu2O nanoclusters were produced via in situ electrochemical reconstruction using Cu–N coordinated MOFs as precursors for the highly selective C2H4 synthesis, showing a Faradaic efficiency of 70.2 ± 1.7% toward C2H4 with a partial current density of 12.38 mA·cm–2 at −1.03 V vs RHE in the CO2RR. In situ infrared spectroscopy with the observation of *CO*CO and *CO*COH intermediates confirmed the C2H4 formation pathway, while in situ Raman spectroscopy, ex situ XPS, and HRTEM evidenced that the coexisting Cu2O and Cu nanoclusters were the active sites. The in situ reconstruction method could be used to synthesize catalysts with high activity and selectivity for CO2 electroreduction.

Boosting CO2 Electroreduction to C2H4 via Unconventional Hybridization: High-Order Ce4+ 4f and O 2p Interaction in Ce-Cu2O for Stabilizing Cu+

“…This distinct observation underscores the good maintenance of Cu + within Ce-Cu 2 O. In situ Raman spectroscopy was further employed to monitor the oxidation of copper in CO 2 -flowed 0.1 M KHCO 3 electrolyte under a potential of −1.3 V, with corresponding devices shown in Figure S17 . As depicted in Figure E, for both Ce-Cu 2 O and pure Cu 2 O, Raman signals at 213, 419, 524, and 624 cm –1 , which are ascribed to the 2 Γ – 12 , 4 Γ – 12 , Γ + 25 , and Γ – 12 + Γ + 25 phonon modes, respectively, were observed. , Notably, the Raman phonon modes (e.g., the 2 Γ – 12 mode) after 120 min were well-retained for Ce-Cu 2 O (Figure E) under genuine operando conditions.…”

Viologen linker as a strong electron-transfer mediator in the covalent organic framework to enhance electrocatalytic CO2reduction

“…Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the morphology of the as-prepared Por(Co)-Vg-COF. 63 The SEM images showed that the Por(Co)-Vg-COF was composed of spherical particles (Fig. S6, ESI †).…”

“…26 To meet the requirements for commercial applications, the excellent CO 2 RR performance of Por(Co)-Vg-COF in neutral electrolyte encouraged us to further improve its electrocatalytic performance with a large current density using a gas-diffusion electrode (GDE) in acidic media, which could offer an avenue to reduce carbonate formation and eliminate CO 2 crossover, and this was the first COF catalyst reported for CO 2 RR in acidic/ alkaline conditions. 37,[63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78] The CO 2 RR of Por(Co)-Vg-COF in 0.06 M H 2 SO 4 with a 0.5 M K 2 SO 4 additive was first tested. As shown in Fig.…”

Metal‐Organic Frameworks (MOFs) and Their Derivatives for Electrocatalytic Carbon Dioxide (CO2) Reduction to Value‐added Chemicals: Recent Advances and New Challenges

“…One point to note in particular is that the genuine active site of the MOF should be meticulously judged when pristine MOFs are subjected to electrocatalytic CO 2 RR, as the MOF structure may evolve under working time. [19][20] For example, Yi et al constructed a porous conductive copper-based metal-organic framework (CuHHTP) for the electrocatalytic CO 2 RR process. [21] As a result of Operando IR spectroscopy and DFT calculations, the in-situ generated Cu 2 O(111) quantum dot is the true active site for electrochemical reduction to CH 4 and is not an independently distributed Cu metal site in CuHHTP.…”

“…More importantly, some MOFs have CO 2 adsorption capacity, which is beneficial to increase the local CO 2 concentration of MOFs during CO 2 RR. One point to note in particular is that the genuine active site of the MOF should be meticulously judged when pristine MOFs are subjected to electrocatalytic CO 2 RR, as the MOF structure may evolve under working time [19–20] . For example, Yi et al.…”