The Tiara Nickel Cluster Story from Theory to Catalytic Applications.

As a transition material between bulk materials and individual atoms, nickel clusters have interesting electrical and structural characteristics that could make them useful as catalysts. To examine the catalytic efficiency of nickel clusters in different applications, this Review combines experimental techniques with density functional theory (DFT). Researchers have shown that nickel clusters can activate and alter tiny molecules like CO, NO, and H through DFT studies that delve deeply into their electronic structures, adsorption mechanisms, and stability. These findings lay the groundwork for the development of effective catalysts for various processes. Nickel clusters considerably improve the hydrogen evolution reaction (HER), indicating their promise for renewable energy conversion. Furthermore, electrocatalysis for the oxygen evolution reaction (OER) showcases the electrochemical performance of nickel clusters, demonstrating their stability and efficiency. The adaptability of nickel clusters is further demonstrated by their use in nitrogen reduction to ammonia. Experimental data confirm that these clusters are good catalysts for this crucial industrial activity. Hydrocarbon reforming and pollutant degradation are two areas in which research has shown that nickel clusters can be useful in thermal reactions. X-ray absorption spectroscopy (XAS) and environmental transmission electron microscopy (ETEM) are examples of in situ characterization techniques that support theoretical predictions by providing real-time insights into the structural alterations and active sites of nickel clusters during these processes. Preparing the way for future research and practical applications in energy and environmental technologies, this thorough study highlights the great potential of nickel clusters in constructing sustainable and efficient catalytic systems.