Competitive adsorption of water and CO on Pd modified Pt electrode from CH3OH solution

Adsorption of CO and water molecules on Pd deposited Pt film (Pd–Pt) electrode was studied in CH3OH or HCOOH solution using ATR-SEIRA spectroscopy. Markedly different adsorbed states were found in comparison with Pt and Ru–Pt surfaces: (1) bulk-like water abruptly desorbed from Pd–Pt surface as the potential increased from −0.2 to 0.0 V; (2) formate, Pt–O–C(H)–O–Pt, on Pd–Pt surface is not concerned with the oxidation of HCOOH at +0.15 V; (3) Ru–Pt surface supplies plenty of water by CO oxidation at Ru domain to accelerate the following oxidation at neighboring Pt sites. It was demonstrated that detailed information and reaction processes on bimetallic catalysis can be elucidated with this method.