Interaction of molecular hydrogen with Ni doped ethylene and acetylene complex

This work reports the interaction of molecular hydrogen with C2H2Ni, C2H4Ni complex and also with their dimer using density functional method. Maximum of two H2 molecules can interact with both C2H2Ni and C2H4Ni complex which corresponds to the gravimetric uptake capacity of 4.54 and 4.44 wt% respectively. No significant difference is observed either in structural parameters or in the adsorption energies after H2 adsorption on C2H2Ni and C2H4Ni complex. The calculated adsorption energies show that, the hydrogen molecules are strongly bound to both C2H2Ni and C2H4Ni complex. The Gibb’s corrected adsorption energies are positive for C2H2Ni(2H2) and C2H4Ni(2H2) complex even at higher temperature. Dimerization of C2H2Ni and C2H4Ni complex was carried out, which has reduced the gravimetric uptake capacity in case of C2H2Ni complex. A strong metal aggregation is observed during the dimerization process. The results from electronic structure method are confirmed using atom-centered density matrix propagation molecular dynamics simulations.

► Hydrogen adsorption on Ni:C2H2 and Ni:C2H4 and their dimer. ► Excellent agreement in results from the theory and experiment. ► In dimers, the metal clustering reduces the H2 uptake. ► Potential application in the area of hydrogen storage for transportation section.