Predicting Catalytic Efficiency of Nickel Nanoclusters: A Surface Activity Parameter Based Approach for Water Splitting

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ABSTRACT

Nickel nanoclusters are crucial catalysts in numerous organic and inorganic reactions. In this study, we theoretically investigate the water-splitting reaction on pristine nickel nanoclusters of varying sizes. We introduce a novel metric, the Surface Activity Parameter (SAP), to systematically assess the catalytic activity of nanoclusters. Our findings reveal that adsorption energy and activation energy for the water-splitting reaction exhibit a size-dependent trend. Specifically, as cluster size increases, adsorption energy becomes more negative, stabilizing the reactant molecules more effectively, while activation energy shows an increasing trend. The relationship between SAP and adsorption energy suggests an inverse correlation, indicating that smaller clusters exhibit higher catalytic efficiency. Furthermore, our analysis shows that the variation in SAP follows an exponential decay with increasing cluster size, demonstrating a predictable trend in catalytic behavior. The study also examines molecular interactions such as bond length elongation, vibrational frequency shifts, and Ni-O bonding characteristics post-adsorption, providing a mechanistic insight into the catalytic activity of nickel nanoclusters. The insights gained from this study could facilitate the rational design of efficient nanocatalysts for water-splitting applications.

Significance of the Study:

Nickel nanoclusters play a pivotal role in catalytic applications, particularly in water splitting, a key process for sustainable hydrogen production. This study introduces the Surface Activity Parameter (SAP), a novel metric for predicting catalytic efficiency based on cluster size. By revealing the relationship between SAP, adsorption energy, and activation energy, this research provides crucial insights into the design of highly efficient nickel-based nanocatalysts. The findings contribute to the development of advanced, cost-effective catalysts for clean energy applications, ultimately aiding the transition toward more sustainable hydrogen production technologies.

Summary of the Study:

This study investigates the catalytic efficiency of nickel nanoclusters in water splitting, introducing the Surface Activity Parameter (SAP) as a predictive metric. The research demonstrates that smaller clusters exhibit higher catalytic efficiency, with SAP following an exponential decay trend as cluster size increases. Key findings include the inverse correlation between SAP and adsorption energy, as well as the influence of molecular interactions such as bond elongation and vibrational frequency shifts. These insights provide a framework for optimizing nickel-based nanocatalysts, facilitating advancements in sustainable energy solutions and hydrogen production.