Hollow Copper Nanocubes Promoting CO₂ Electroreduction to Multicarbon Products

Abstract

Electrochemical carbon dioxide reduction reaction (CO2RR) to multicarbon (C2+) compounds holds great potential for achieving carbon neutrality and storing intermittent renewable energy. The formation of carbon–carbon (C–C) bonds, affected by the concentration of *CO intermediates on the surface of catalysts, is critical to facilitate the production of C2 species. Here, a novel method to prepare uniform hollow oxide-derived copper crystals is reported, reducing CO2 to C2 products (ethylene and ethanol) with an outstanding Faradaic efficiency of 71.1% in 0.1 M KHCO3. The degree of hollowness shows a positive tendency to C2 selectivity but negative to H2 and C1 selectivity. In situ surface-enhanced infrared absorption spectroscopy indicates that hollow structures enhance localized *CO concentration, boosting C–C coupling for producing C2 products. This provides a feasible strategy to enrich important intermediates to deeper reduction products through catalyst structure engineering.

Multiscale CO2 Electrocatalysis to C2+ Products: Reaction Mechanisms, Catalyst Design, and Device Fabrication

“…Two-dimensional nanosheets with highly exposed catalytic sites possibly result in better utilization of reactive gas or intermediates . Three-dimensional structures with hollow cavities endow the catalysts with spatial confinement ability to facilitate the retention of intermediaries. , …”

“…186 Three-dimensional structures with hollow cavities endow the catalysts with spatial confinement ability to facilitate the retention of intermediaries. 188,189 Hierarchical structures, capable of providing high surface roughness with their micro/nanoarchitectures, present an excellent solution to suppress parasitic hydrogen evolution, possibly due to the immediate consumption of protons around catalyst surfaces and the accumulation of OH − . Gao's recent work displayed the construction of hierarchically dendritic Cu electrodes, as pictured in Figure 8G, mimicking setaria leaves that maintained a high hydrophobicity, leading to enhanced gas−liquid−solid triphase boundaries and omnidirectional transport of CO 2 .…”

Stabilizing Cu Catalysts for Electrochemical CO2 Reduction Using a Carbon Overlayer

“…It is a promising carbon-neutral technology to produce useful chemicals via CO 2 electroreduction reaction (CO 2 RR) using renewable electricities. Multicarbon products (C 2+ ) are preferred for their high market values and energy densities. − Copper is the only monometallic catalyst able to produce C 2+ products due to its moderate adsorption energy of key reaction intermediate *CO on surfaces for further deep reduction and C–C bond formation. − …”

Cu2S Nanoparticle-Modified Copper Hydroxide Nanowire Arrays for Optimized Electrochemical CO2 Reduction Selectivity

“…9−12 During the electrochemical conversion of CO 2 into valuable chemicals and fuels, catalysts play a crucial role in the activity and selectivity of products. 5,10,11,13,14 In particular, formate is a valuable liquid fuel with high energy density used in industry, whose consumption has significantly increased in the past decade. 3,15 Until now, various catalysts containing transition metals, noble metals, and their oxides have been explored to reduce overpotential and obtain desired products.…”

“…Effective carbon sequestration and storage technologies are urgently needed to mitigate the growing imbalance in the carbon cycle caused by the massive use of fossil fuels. − The electrochemical CO 2 reduction reaction (ECO 2 RR) is highly preferred for its easy implementation and high conversion efficiency. − Compared with the direct synthesis of multicarbon oxygenates requiring high potential, , the formation of single carbon products (CO and formate) is more feasible for economic CO 2 conversion. − During the electrochemical conversion of CO 2 into valuable chemicals and fuels, catalysts play a crucial role in the activity and selectivity of products. ,,,, In particular, formate is a valuable liquid fuel with high energy density used in industry, whose consumption has significantly increased in the past decade. , Until now, various catalysts containing transition metals, noble metals, and their oxides have been explored to reduce overpotential and obtain desired products. − Among them, copper-based catalysts have attracted great attention for their high reductive activity to useful chemicals, such as CO, formic acid, methanol, ethylene, ethanol, and even hydrocarbons containing more carbon atoms. − However, the intrinsic disadvantages of traditional copper catalysts, low electrode energy efficiency and poor selectivity, tremendously hamper their further development.…”