The technique identifies and measures short-lived intermediate steps in the chemical conversion of the greenhouse gas into energy-rich products.
Researchers have been converting CO2 into fuel for more than a century using a process known as electrochemical reduction, but so far none of the methods used have been efficient enough to be scaled up to a global industrial scale. Electro-catalysts are crucial elements in the reduction process, but the mechanisms by which they operate are often unknown, making it hard for researchers to design new methods.
This new technique, which is the result of a collaboration between STFC's Central Laser Facility (CLF) and Scientific Computing Department, and the University of Liverpool's Stephenson Institute for Renewable Energy, has enabled unprecedented insights into the mechanism of operation for a specific electro-catalyst, with great potential for efficient CO2 reduction. It has brought the possibility of improving the electro-catalyst and upscaling CO2 conversion on a commercial scale a step closer.
Building on an earlier project using the ULTRA laser at STFC's Rutherford Appleton Laboratory, the CLF and Liverpool scientists used electrochemical Sum-Frequency Generation (SFG) spectroscopy to observe the electo-catalyst and its related chemical reactions as they happened.
The resulting data from this experiment was then sent to Dr Gilberto Teobaldi in STFC's Scientific Computing Department, who used advanced computer simulations to interpret the behaviour of the electro-catalyst as measured by the laser technique.
Dr Paul Donaldson at CLF said, “This work was the first success of the group in electrochemical SFG and involved several years of careful experimentation, finally revealing with unprecedented detail and specificity some of the steps in the catalyst's chemical reactions and paving the way for using the SFG technique more generally in the field of electro-catalysis science."
The technical advance is the first-ever measurement of the intermediates involved in the reaction between CO2 and the electro-catalyst to yield forms of carbon that can be further processed into chemical fuels.
Dr Teobaldi said, “Commercialization of scalable electro-catalytic technologies for CO2 recycling demands development of a new generation of improved electro-catalysts for the process. For such a development, atomic-scale understanding of the functioning of the electro-catalyst is highly desirable, if not essential. By introducing a new combined experimental and simulation approach capable of unprecedented insights into electro-catalytic reactions, this study moves important steps towards the realisation of practical CO2 recycling technologies".
Notes for editors:
The paper 'Detection of catalytic intermediates at an electrode surface during carbon dioxide reduction by an earth-abundant catalyst' is published in Nature Catalysis [DOI: 10.1038/s41929-018-0169-3]. Read a free-to-view version
Earlier results from the ULTRA laser experiment