Insights into catalytic behavior of TiMgn (n=1–12) nanoclusters in hydrogen storage and dissociation process: A DFT investigation

Abstract

The present study reports the insight of the catalytic behavior of TiMgn (n = 1–12) nanoclusters in hydrogenation and dissociation reaction mechanism under density functional theory (DFT) investigation. From the variation of thermodynamic and chemical parameters during growth process of TiMgn, 18-electron TiMg7 cluster is found as the most stable with orbital sequence 1S21P61D10. However, after hydrogenation TiMg5 is found as the most efficient catalyst in hydrogenation and dissociation reaction. Following the calculated IRC path of the hydrogenation reaction process (H2+TiMg5→TiMg5–2H), it is found that the low activation barrier and reaction energy helps in hydrogenation-dissociation process; and also in the reduction of dehydrogenation temperature. Calculated ELF confirms that the dissociated hydrogen tends to localize on the outer surface of the TiMg5 cluster. The present investigation provides strong evidence of efficient catalytic behavior of TiMg5 in hydrogenation process. The findings are important for designing TiMgn based catalyst in hydrogen storage and dissociation reaction.