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New electrocatalyst converts CO2 into ethanol, acetone, and n-butanol with high efficiency

The electrocatalytic conversion of CO2 using renewable energy could establish a climate-neutral, artificial carbon cycle. Excess energy produced by photovoltaics and wind energy could be stored through the electrocatalytic production of fuels from CO2. These could then be burned as needed. Conversion into liquid fuels would be advantageous because they have high energy density and are safe to store and transport. However, the electrocatalytic formation of products with two or more carbon atoms (C2+) is very challenging.

Now, researchers in China have developed a new electrocatalyst that yields ethanol, acetone, and n-butanol as major products with a total C2-4 faradaic efficiency of about 49 % at −0.8 V vs. reversible hydrogen electrode (RHE), which can be maintained for at least 3 months. A paper on the development is published in the journal Angewandte Chemie.


Credit: Angewandte Chemie

To make the electrocatalyst, the team from Foshan University (Foshan, Guangdong), the University of Science and Technology of China (Hefei, Anhui), and Xi’an Shiyou University (Xi’an, Shaanxi), led by Fei Hu, Tingting Kong, Jun Jiang, and Yujie Xiong, etched thin ribbons of a copper/titanium alloy with hydrofluoric acid to remove the titanium from the surface.

This results in the material a-CuTi@Cu, with a porous copper surface on an amorphous CuTi alloy. It has catalytically active copper centers with remarkably high activity, selectivity, and stability for the reduction of CO2 to C2+ products. In contrast, pure copper foil produces C1 products but hardly any C2+ products.

The reaction involves a multistep electron-transfer process via various intermediates. In the new electrocatalyst, the inactive titanium atoms below the surface actually play an important role; they increase the electron density of the Cu atoms on the surface. This stabilizes the adsorption of *CO, the key intermediate in the formation of multicarbon products, allows for high coverage of the surface with *CO, and lowers the energy barrier for di- and trimerization of the *CO as new carbon–carbon bonds are formed.


  • Hu, F., Yang, L., Jiang, Y., Duan, C., Wang, X., Zeng, L., Lv, X., Duan, D., Liu, Q., Kong, T., Jiang, J., Long, R. and Xiong, Y. (2021), “Ultrastable Cu Catalyst for CO2 Electroreduction to Multicarbon Liquid Fuels by Tuning C–C Coupling with CuTi Subsurface.” Angew. Chem. Int. Ed..



'a total C2-4 faradaic efficiency of about 49 % at −0.8 V vs. reversible hydrogen electrode (RHE), which can be maintained for at least 3 months.'

I'd be grateful if those with a technical background here could or would translate this for those of us who are not knowledgeable into terms more understandable regarding its practicality and energy use.

Arnold Garnsey

I'm guessing this is about recycling carbon from a carbon stream that might be considered suitable for sequestration the largest which is from Fossil fuel extraction coal gas etc. There is no mention of the C source only that this process is carbon neutral as if that is 'better? than the carbon were released. If my guess is correct it will be a tied to and a part of fossil fuel extraction and process so not necessarily carbon neutral in practice. I'm going on the language used not the chemistry behind the paywall.

Arnold Garnsey

Could be steam methane to H2 related.



The reversible hydrogen electrode (RHE) refers to how they made their measurements.


The C2-C4 refers to the products. C2 is ethanol, C2H5OH. C3 is acetone, C3H60. C4 is butanol, C4H9OH. I believe that the -0.8V refers to excess potential required to get the reaction to go. I believe that the excess potential multiplied by the current is the lost energy that results in 49% efficiency.

Having said all of this, it is a long time since I have taken chemistry and physical chemistry. My undergraduate degree was in physics and my graduate degrees were in Mechanical Engineering.

This was probably more of a university research project than a shovel-ready practical endeavor but overall I think that more research is better as that is the how most of the practical projects start.


Good reply thanks


C3 alcohol is propanol, of which acetone is an isomer.


Correction:  acetone is not an isomer of propanol.  Acetone is C3H6O; propanol is C3H8O.

Roger Pham

A Faradic efficiency of 49% is worthless as a potential energy storage means. By comparison, electrolysis of water has Faradic efficiency of almost 90%.
It is important that the electrons added to an electrolyzer are used to drive the water-splitting reactions and not side reactions such as corrosion of the electrodes or the production of hydrogen peroxide. The production of the desired products results in a high Faradic efficiency. Of course, overvoltages also result in the production of heat rather than in the formation of the desired products. Losses that reduce the Faradic efficiency result in products other than hydrogen or oxygen. The Faradic efficiency is sometimes referred to as the Coulombic or current efficiency.
For good Faradic efficiency in water electrolysis, the electrodes must be stable against oxidation or reduction versus the HER and OER reactions. In commercial electrolyzers that must last for many years this problem has been very well addressed and the side reactions are very minor.

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