DFT calculation of vibrational frequency of hydrogen atoms on Pt electrodes: Analysis of the electric field dependence of the Pt–H stretching frequency

The electric field dependence of vibrational frequency of H atoms on Pt electrodes was investigated by performing DFT calculations for the Pt13 cluster with an adsorbed atop H atom under external fields. Calculations with and without the solvent effect depending on dielectric constant showed that the external field, which was significantly enhanced by the solvent effect, affects Pt–H stretching frequency by causing electron transfer between the Pt–H bond and the cluster. Our results agree semi-quantitatively with the large Pt–H frequency change observed experimentally and can be systematically explained in terms of the effective field around the Pt–H bond.