Hydrogen storage in small size MgnCo clusters: A density functional study

•We model MgnCo clusters useful as hydrogen storage materials using DFT calculations.•We studied BE, FE, Δ2, REC path, VIP, VEA, adsorption & chemisorptions energy etc.•H2-Mg5Co shows highest chemi. energy in IRC path & it is same as activation barrier.•All results supports to take Mg5Co suitable as effective hydrogen catalysis element.•The results have theoretical and technological importance as a first study of this kind.

The present study reports the use MgnCo (n = 1–10) hybrid nanoclusters as hydrogen storage using density functional theory (DFT) calculation method. From the variation of the thermodynamic parameters of the clusters Mg4Co and Mg6Co are found stable in the series, whereas, after absorption of hydrogen, the higher stability shifted to H2-Mg5Co. It is found that after reaction with the cluster, hydrogen atoms adsorbed with Co atom in MgnCo clusters to form MgnCoH2 that gives a better option in hydrogen catalysis. By the calculated values of chemisorptions and physisorptions energies; VIP and VEA parameters, we found Mg5Co can be used as effective hydrogen catalysis. Calculated chemisorptions energy of the H2-Mg5Co cluster is found maximum in the series. The calculated activation barrier energy of H2-Mg5Co has been verified by the study of intrinsic reaction coordinates (IRC) pathway between Mg5Co and H2.

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