Industrial-Current-Density CO₂-to-C₂₊ Electroreduction by Anti-swelling Anion-Exchange Ionomer-Modified Oxide-Derived Cu Nanosheets

Abstract

CO2 electroreduction to high-energy-density C2+ products is highly attractive, whereas the C2+ selectivity under industrial current densities is still unsatisfying. Here, an anti-swelling anion exchange ionomer (AEI) was first proposed to optimize the local environment for promoting industrial-current-density CO2-to-C2+ electroreduction. Taking the anti-swelling AEI-modified oxide-derived Cu nanosheets as an example, in situ Raman spectroscopy and contact angle measurements revealed that the OH–-accumulated -N­(CH3)3 + groups and anti-swelling backbone of AEI could synergistically regulate the local pH level and water content. In situ Fourier-transform infrared spectroscopy and theoretical calculations demonstrated that the higher local pH value could lower the energy barrier for the rate-limiting COCO* hydrogenated to COCOH* from 0.08 to 0.04 eV, thereby boosting the generation of C2+ products. Owing to the anti-swelling backbone, the optimized water content of 3.5% could suppress the competing H2 evolution and hence facilitate the proton-electron transfer step for C2+ production. As a result, the anti-swelling AEI-modified oxide-derived Cu nanosheets achieved a C2+ Faradaic efficiency of 85.1% at a current density up to 800 mA cm–2 with a half-cell power conversion efficiency exceeding 50%, outperforming most reported powder catalysts.

Asymmetric Low-Frequency Pulsed Strategy Enables Ultralong CO2 Reduction Stability and Controllable Product Selectivity

“…Therefore, we employed the in situ Raman experiment to explore the local pH (Figures S32 and S33). The Raman peaks of HCO 3 – (1014 cm –1 ) and CO 3 2– (1066 cm –1 ) were quantified to measure the surface pH value (Figure S33). , For ALPS-1, the HCO 3 – peak was prominent.…”

A Porous π–π Stacking Framework with Dicopper(I) Sites and Adjacent Proton Relays for Electroreduction of CO2 to C2+ Products

“…As a crucial segment of industrial production, the manufacture of C 2+ products ( e.g. , C 2 H 4 , EtOH, AcOH, and PrOH) plays an important role in economy. − Recently, electrochemical CO 2 reduction (ECR) has attracted much attention thanks to its potential application for the production of hydrocarbons and carbon oxygenates, − especially C 2+ compounds, and the achievement of carbon neutrality. − However, electrochemical production of C 2+ compounds generally suffers from poor stability, product selectivity and efficiency, and the reaction mechanism still remains to be explored . Therefore, the design and preparation of new electrocatalysts for yielding C 2+ products should be regarded as one of the most important challenges for the application of ECR.…”

Recent advances in CO2 capture and reduction

“…92,95 Recent studies have suggested that the key active components are Cu-Cu 2 O mixtures, as observed in the CO 2 RR studies on partially oxidized Cu electrode. [108][109][110][111] Cu(I) and residual subsurface oxygen species are considered to play important roles towards enhanced performance. The oxidation state of Cu can be reversibly transformed between Cu(0) and Cu(I) under the electrochemical reaction conditions.…”