Recent advancements in renewable energy storage have pointed to dual-atom catalysts (DACs) as pivotal players. Particularly, research focusing on asymmetric selenium-based DACs has showcased remarkable efficiency enhancements for the oxygen reduction reaction (ORR). The innovative approach aims to overcome existing catalytic barriers, paving the way for broader applications.
Renewable energy technologies, including metal–air batteries and fuel cells, play a significant role in reducing dependency on fossil fuels. Oxygen reduction reactions, central to these technologies, traditionally suffer from sluggish kinetics, which hampers their performance. By refining the design of DACs, researchers have sought to optimize kinetic performance and overall power outputs.
Leveraging the benefits of heteronuclear interactions, this study introduces DACs with selenium and metal active sites, termed heteronuclear SeN2–MN2 (M = Fe, Mn, Co, etc.). The incorporation of selenium optimizes the electronic structure, resulting in favorable polarization of charge distribution across metal sites, thereby enhancing catalytic activity.
The study highlights the synthesis process wherein various selenium-based DACs, synthesized through rigorous spectroscopic characterization and theoretical calculations, are compared to traditional single-atom structures. Notably, the SeFe dual-atom catalysts exhibited superior alkaline ORR performance, achieving half-wave potentials of 0.926 V versus the reversible hydrogen electrode (RHE).
To ascertain the efficiency gains, the research team conducted detailed investigations using laboratory controls. Results indicated significantly enhanced electrochemical activity, demonstrated by practical applications within zinc-air batteries, which showcased maximum power densities as high as 287.2 mW cm-2.
One of the authors of the study noted, "The Se modulator can regulate the local coordination configuration and the electronic structure of central Fe sites by triggering a polarised charge distribution." This innovative design equips the DACs with refined properties reducing reaction energy barriers during ORR, contributing to their elevated performance metrics.
While many studies have focused on either dual-metal or single-atom catalysts, the discovery of the selenium-iron paired sites emphasizes the importance of experimental verifications combined with computational insights. The dual-atom strategies enable rigorous control over atomic spacing and electronic interactions, producing well-defined active sites with potentially transformative properties for catalysis.
Results showed dual-atom configurations not only reduced electrochemical transfer resistance but also improved catalytic stability, indicating promising applications for sustainable energy storage methodologies. After extensive testing, the assembled zinc-air battery displayed exceptional durability and longevity, retaining 84% of the original current after prolonged operation.
This research demonstrates how advanced materials can lead to significant improvements in energy conversion and storage technology. By refining the structural nuances of DACs, future research may explore broader applications of these catalysts across varied fields of renewable energy.
To conclude, the innovative design and implementation of dual-atom catalysts with selenium highlights pathways to achieving efficient oxygen reduction reactions. This study provides valuable perspectives and methodologies necessary for driving forward the next generation of sustainable energy technologies.