There’s no question that researchers have achieved astounding advances in the knowledge and art of electrochemically reducing carbon dioxide (CO2). This process has long fascinated scientists for decades. This revolutionary research aims to turn CO2 and water into useful fuels and chemicals. Perhaps most importantly, it emphasizes the key role that copper catalysts play in this transformation. These discoveries would help in the development of more effective and targeted strategies to produce liquid fuels from renewable materials.
The CO2 electrochemical reduction reaction (CO2RR) is an innovative approach that seeks to address global energy challenges by creating sustainable fuels. Copper has turned out to be a high performing catalyst in this process. It is central to the process of taking CO2 and water and turning them into valuable feedstocks for products like ethylene and ethanol. These changes are critical for creating other forms of energy and moving away from fossil fuels.
Even with the promise of copper catalysts, scientists have struggled with performance degradation over time. What’s been less clear until now are the exact chemical and physical processes that have led to this decline in coral health. Since 2020, a partnership between seven institutions has generated transformative knowledge on catalyst degradation. This progress has been made by applying small-angle X-ray scattering, SAXS, techniques to the copper catalyst system.
To maximize their understanding of this complex CO2RR reaction, the research team incubated for a full hour. Walter Drisdell of Berkeley Lab’s Chemical Sciences Division was a major player in this push. Input from Tsinghua Researchers determined that the particle size distribution of the catalysts evolves significantly in the first 12 minutes. That transition is mainly powered by an economic phenomenon known as particle migration and coalescence (PMC). Beyond that first regeneration phase, researchers noticed the process transitioning to Ostwald ripening. Through this process, smaller nanoparticles dissolve and redeposit on larger particles. Much like the development of sand-like crystals of ice in ice cream, this process is tied to molecular movement.
“Our approach allowed us to explore how the nanoscale size distribution evolves as a function of operating conditions, and to identify two different mechanisms that we can then use to guide our efforts to stabilize these systems and protect them from degradation,” – Walter Drisdell.
These research findings offer guidance into approaches that can be taken to minimize performance loss in copper catalysts. Drisdell identified a number of possible strategies for improving catalyst stability, stressing the need to tailor approaches to the specific operating environment.
“These results suggest various mitigation strategies to protect catalysts depending on the desired operating conditions, such as improved support materials to limit PMC, or alloying strategies and physical coatings to slow dissolution and reduce Ostwald ripening,” – Walter Drisdell.
This study is more than a mere academic’s interest. It could prove to be as important for the future of artificial photosynthesis and sustainable energy production. Both approaches would help researchers design better systems for turning waste CO2 into recyclable fuels. They do this by developing a deeper understanding of the macroscopic mechanisms that govern catalyst performance.