Acid-base and nucleophilic chemistry of atomic oxygen on the Au(110) surface: Reactions with formic acid and formaldehyde

The adsorption of formic acid and formaldehyde on clean and oxidized Au(110) surfaces was investigated with temperature programmed reaction spectroscopy. Each molecule molecularly adsorbed on the clean Au(110) surface with monolayer binding energies of 13 and 10 kcal mol−1, respectively. Formic acid reacted with oxygen adatoms below 210 K in a typical Brønsted acid-base reaction to form water and adsorbed formate (HCOO). The formate decomposed at 340 K to evolve water, carbon dioxide, and formic acid with an activation energy of 20 kcal mol−1. Formaldehyde also reacted with oxygen adatoms in a nucleophilic reaction below 210 K to form water, hydrogen, and formate groups. These reactions are directly analogous to reactions of atomic oxygen adsorbed on the other group IB metals, copper and silver and demonstrate that oxygen adatoms on all of the group IB metals exhibit Brønsted basicity and nucleophilicity.