The chemisorption of oxygen,water and selected hydrocarbons on the (111) and stepped gold surfaces

The dissociative chemisorption of oxygen and water is reported on both (111) and 6(111) × (100)] crystal faces of gold. The oxide formation becomes rapid above 500°C at pressures of about 10^?6 torr. The resulting gold oxide is bound strongly. It is similar in structure to the corresponding sulphide and is stable on both surfaces to 800°C in vacum. Ethylene, cyclohexene, n-heptane, benzene did not chemisorb on gold under low pressure conditions on either the (111) or on the stepped gold surface while naphthalene exhibited dissociative chemisorption on both types of surfaces. Hydrocarbon fragments are bound strongly to the gold surface but the activation energy for dissociative adsorption of light hydrocarbon molecules appears to be high.