We might be looking at a brighter future for our air quality, thanks to copper nanoclusters that could help us cut down carbon emissions through an electrochemical process.
Although copper (Cu) doesn’t have the glamorous image of gold or silver, its incredible adaptability makes it essential for advanced research. A joint effort by scientists from Tohoku University, the Tokyo University of Science, and the University of Adelaide has revealed a revolutionary technique to improve the selectivity and sustainability of electrochemical CO2 reduction methods. By manipulating the surfaces of Cu nanoclusters (NCs) at the atomic level, this team has opened the door to more effective and environmentally friendly carbon conversion technologies. This advancement not only highlights the transformative capabilities of Cu in sustainable chemistry but also emphasizes the significant role of global partnerships in tackling urgent issues like carbon emissions.
The findings were published in Small on December 4, 2024.
Electrochemical CO2 reduction reactions (CO2RR) have gained considerable interest lately for their ability to convert excess atmospheric CO2 into useful products. Among various nanocatalysts examined, NCs have stood out due to their unique benefits compared to larger nanoparticles. Within this group, Cu NCs have shown significant potential, allowing for a variety of product formations while maintaining high catalytic efficiency and sustainability. However, achieving precise control over product selectivity on an industrial scale presents challenges. Consequently, research is currently focused on improving these characteristics to maximize the effectiveness of Cu NCs for sustainable CO2 conversion.
“To reach this significant advancement, our team needed to adjust the NCs at the atomic level,” states Professor Yuichi Negishi from Tohoku University. “This was quite difficult because the shape of the NCs relied heavily on the specific components we needed to modify. It was similar to trying to shift a key support beam of a structure.”
They successfully created two Cu₁₄ NCs that maintained the same structural framework by changing the thiolate ligands (PET: 2-phenylethanethiolate; CHT: cyclohexanethiolate) on their surfaces. Overcoming this challenge involved developing a precisely controlled reduction strategy, which allowed the creation of two structurally identical NCs but with different ligands — a significant milestone in NC design. Despite these breakthroughs, the team noticed differences in stability among these NCs, which were linked to variations in the interactions between clusters. These differences are crucial in determining the sustainability of these NCs during catalytic tasks.
Even though these NCs possess nearly identical shapes due to their two distinct thiolate ligands, they show significantly different product selectivity in tests for CO2 reduction. These variations affect the overall effectiveness and selectivity of the CO2RR.
Negishi concludes, “These discoveries are crucial for advancing the design of Cu NCs that merge durability with high selectivity, setting the stage for more effective and dependable electrochemical CO2 reduction technologies.”
