Hydrogen uptake capacity of C2H4Sc and its ions: A density functional study

We report the gravimetric hydrogen uptake capacity of C₂H₄Sc complex and isoelectronic ions using Density Functional Theory. We predict that C₂H₄Sc⁺ can bind maximum seven hydrogen molecules in dihydrogen form giving gravimetric uptake capacity of 16.2 wt %, larger by about 2 and 4 wt % than the neutral and anion, respectively. We also found that the interaction of hydrogen molecules with C₂H₄Sc⁺ ion is characteristically different than that with neutral and anion. Vibrational spectroscopic study reveals that C₂H₄Sc and isoelectronic ions are quantum mechanically stable with their characteristic change in respective identified mode. The large gravimetric H₂ uptake capacity of C₂H₄Sc⁺ is well above the target specified by Department of Energy (DOE) by 2015. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010