Methanol Adsorption on PtCo(111). A DFT Study

V. ORAZI; P. BECHTHOLD; E. GONZÁLEZ; P. JASEN; A. JUAN

Dailan

Conferencia; ICASS 2017 2nd International Conference on Applied Surface Science; 2017

The use of methanol as fuel has several advantages in comparison to hydrogen: it is a cheap liquid fuel,easily handled, transported, and stored, and with a high theoretical energy density. Pt is the most activemetal for methanol electrooxidation. However, its low abundance, high cost limit commercial applicationsand its performance are far from acceptable for their use as electrode in fuel cells. The alloying of Pt withCo have comparable and even better catalytic activity. The molecule is adsorbed at 2.24 Å over the surface. The C-O-Co angle decrease to 142° and the H-C-Oangle is about 109°. The molecule presents a small distortion after adsorption. The C-Hbonds are strengthened whereas the C-O and O-H bonds are weakened. The C-O BO decrease about 12%while the O-H between 16% and 24%. The TDOS curves present small peaks at -22.3, -13.0 and -8.7 eV related to methanol. Theshift of the black curve to lower energies indicates that methanol is stabilized after adsorption and that theinteraction is mainly through the Co atom. The vibrational frequencies for methanol present a red shift compared to gas-phase.The main result is the favourable interaction of methanol with the surface. The starting point for methanol reaction would be the O-H bond weakening followed by intermediary?s methoxy species.