New high-selectivity catalyst converts CO2 to ethylene 

In Germany, a team headed by Prof Dr Beatriz Roldan Cuenya from Ruhr-Universität Bochumsaid that how plasma-treated copper can be used as a catalyst to performs highly selective conversion of the greenhouse gas carbon dioxide into ethylene – an important source material for the chemical industry. The report was published in Nature Communications.

PhD student Hemma Mistry from the Institute for Experimental Physics IV in Bochum used copper films treated with oxygen or hydrogen plasmas as catalysts. Through these plasma treatments, she altered the properties of the copper surface, rendering it rougher or less rough, for example, and oxidizing the material. The researcher varied the plasma parameters systematically until she hit on the optimal surface properties.

Her best catalyst boasts a higher ethylene production rate than traditional copper catalysts. At the same time, it acts in a highly selective manner, which means that the amount of unwanted side products is considerable reduced. “It’s a new record for this material,” concludes Beatriz Roldan Cuenya.

The researchers also identified the reason why this form of plasma treatment has been successful. Using synchrotron radiation, they analysed the copper film’s chemical state during the catalysis of the reaction. Through these measurements, they detected the cause of the higher ethylene selectivity. The key component was positively charged copper ions at the catalyst surface.

“The results open up new possibilities for designing catalysts on the nanoscale with specific activity and selectivity,” says Beatriz Roldan Cuenya.