Sparse layers of 10-nanometer silver particles boost CO production from CO₂

Researchers at Helmholtz Association in Germany have discovered that using 10-nanometer thick silver particles can significantly increase the production of carbon monoxide (CO) from carbon dioxide (CO₂) through electrolysis. The study, published in Advanced Functional Materials, found that nanoparticles of this specific size and density on a carbon electrode yielded the highest CO output.

The team led by Prashanth Menezes at HZB conducted experiments varying the size and concentration of silver nanoparticles on a carbon powder material coating the carbon electrode. They discovered that particles with diameters around 10 nm, when distributed loosely over the carbon material, produced the optimal amount of CO.

In addition to improving CO production, the researchers also optimized the process by introducing a chemical reaction at the anode. By replacing the typical oxygen evolution reaction with an aldehyde oxidation reaction, they were able to reduce energy consumption by more than 30%. This modification also resulted in the simultaneous production of hydrogen gas and valuable carboxylic acids like formic acid, alongside the CO.

With CO and hydrogen generated during the electrochemical process, these can be utilized as building blocks for creating sustainable fuels and chemicals. The team from HZB is collaborating with partners in South Africa as part of the GreenQUEST project to develop an affordable and sustainable green cooking fuel, aiming to provide a cleaner alternative to traditional biomass-based cooking, particularly in rural areas where firewood remains a primary energy source.