Electrochemical conversion of CO₂ into value-added chemical fuels driven by renewable electrical energy has roles in reducing net CO₂ emission and in addressing energy consumption.

Although considerable progress has been made in CO₂ electroreduction, carbonate formation can cause serious CO₂ loss. CO₂ conversion in acidic electrolyte is an attractive way to overcome the problem of CO₂ loss, however, selective reduction remains a challenge.

In a study published in Energy & Environmental Science, a research team from the Shanghai Advanced Research Institute (SARI) of the Chinese Academy of Sciences designed a Cu hollow fiber penetration electrode to electroreduce CO₂ in strong acid with effective inhibition of hydrogen evolution reaction (HER).

By virtue of the unique penetration effect induced by Cu hollow fiber, abundant CO₂ molecules were supplied to Cu active sites. The Cu surface possessed enough high CO₂ coverage, which suppressed HER and facilitated CO₂ reduction to C₂⁺ products.

Thus, a CO₂ single-pass conversion rate exceeding 51% with a C₂⁺ Faradaic efficiency of 73.4% and partial current density of 2.2 A cm^-2 were achieved in acidic solution (pH = 0.71). The performance of the Cu penetration electrode was approximated to or even exceeded those of the state-of-the-art Cu base catalysts.

This work represents progress in the design and development of new electrode configurations to realize CO₂ electroreduction to high-value C₂⁺ chemicals with scalable applications.

More information: Chang Zhu et al, Selective CO₂ electroreduction to multicarbon products exceeding 2 A cm⁻² in strong acids via a hollow-fiber Cu penetration electrode, Energy & Environmental Science (2023). DOI: 10.1039/D3EE02867D

Journal information: Energy & Environmental Science

Provided by Chinese Academy of Sciences