D₂O Adsorption and Reaction on Clean and Oxygen Covered Electrolytic Silver

The adsorption and reaction of D₂O on electrolytic silver have been studied by temperature programmed reaction spectroscopy （TPRS）, thermal desorption spectroscopy （TDS） and measurement of work function change in UHV. The results show that on dean silver, there is a little chemisorption of D₂O and that the preadsorbed oxygon can promote the adsorption of D₂O greatly, resulting in an adsorbed complex compound OD（D₂O）_n on the surface. There is a good linear relationship between the amount of adsorbed D₂O and preadsorbed oxygen coverage. Two D₂O peaks can be found in TPRS figure: one is related to the molecular water species and its peak temperature is 470±4K; the other is related to dissociated water species and its peak temperature is 641K. It has been found that the adsorption of molecular water （D₂O） and dissociated water may decrease and increase the surface work function respectively.