Authors: Keabetsoe Manosa
Source: ChemRxiv (preprint, 2025-07-30)
Field: Materials Science — Materials Chemistry

The comparison in the degree of economic feasibility, effectiveness, safety and the proximity to the optimum conditions needed for the maximum storage of hydrogen gas in AB2-type cluster systems of Magnesium-Titanium and Magnesium-Nickel based on the relevant physical and chemical properties: The Mpoetsi Manosa study. The development and refinement of bimetallic clusters for emerging applications such as hydrogen storage necessitate a thorough consideration of their economic viability, operational efficiency, and safety parameters. This investigation focuses on AB₂-type clusters within Magnesium-Nickel and Magnesium-Titanium systems—specifically MgNi₂, NiMg₂, MgTi₂, and TiMg₂—to identify the most promising candidate for future deployment. By integrating advanced computational chemistry methods with economic modeling, this study aims to evaluate the practical potential of these clusters in next-generation technologies. Economically, data on historical market prices for Magnesium, Nickel, and Titanium spanning the last 15 years were collected and analyzed. Employing both linear and polynomial regression models for Time Series Analysis, I forecasted future price trends. Model effectiveness was assessed using the coefficient of determination (R²) and the Akaike Information Criterion (AIC) to ensure the robustness of the chosen models. These analyses were performed using Microsoft Excel. Results indicated that, despite its superior chemical properties, Titanium is projected to be greatly more costly than Nickel over the next 20 years. Consequently, Magnesium-Titanium clusters appear less economically favorable compared to Magnesium-Nickel counterparts. Regarding chemical efficiency, Density Functional Theory (DFT) calculations were carried out employing the B3LYP functional combined with the def2-SVPD basis set. All calculations assumed a neutral charge with multiplicities ranging from 1 to 3. Geometry optimizations and vibrational frequency analyses were performed through ChemCompute to identify most stable structures based on binding energy and infrared spectra. Electronic structure analyses included Mulliken charge evaluations to understand electron distribution and reactive hotspots. The theoretical gravimetric hydrogen storage capacity was also estimated by assuming two H₂ molecules per cluster, with accessible molecular surface areas calculated via MOPAC in Winmostar V11.11.4. Notably, the TiMg₂ cluster demonstrated the most advantageous attributes: a stable geometry, optimal electron distribution, highest theoretical gravimetric density, and considerable surface area, indicating its superior potential for hydrogen storage or catalytic purposes. Safety and reactivity considerations were analyzed using global reactivity descriptors derived from Koopmans’ theorem approximations. These included electronegativity (χ), chemical hardness (η), and electrophilicity index (ω). Higher electronegativity and hardness were interpreted as indicators of greater stability and lower reactivity, while enhanced electrophilicity suggested increased reactivity and potentially reduced safety. Among the clusters, TiMg₂ again showed the greatest stability and moderate reactivity, followed by NiMg₂. In summary, although MgNi₂ and NiMg₂ clusters are more economically appealing due to the lower cost of Nickel, the TiMg₂ system emerges as overall the most promising when considering stability, efficiency, and safety. Despite higher predicted costs, the TiMg₂ cluster exhibits attributes that make it a compelling candidate for further exploration in hydrogen storage and catalytic applications. Hydrogen storage ; Degree (music) ; Cluster (spacecraft) ; Magnesium ; Computer science ; Hydrogen ; Environmental science ; Materials science ; Chemistry ; Physics ; Operating system ; Metallurgy ; Acoustics Hydrogen Storage and Materials ; Ammonia Synthesis and Nitrogen Reduction ; Magnesium Alloys: Properties and Applications