Effects of Anions on Hydrogen Electrosorption on Platinum Single-Crystal Electrodes

摘要

Hydrogen adsorption on the three low index planes of single crystal Pt has been investigated using a technique which involves annealing in a H2 flame and transfer through the air into the electrolyte. The results have been compared with those obtained with a special vacuum transfer system and have been found to be essentially identical for the (100), (110), and (111) planes of Pt. The effects of adsorbed anions such as NO3(-) and C1(-) are very pronounced even at very low concentrations (.000001/M). At C1(-) concentrations of > or = .001/m the voltammetry curves for hydrogen adsorption-desorption are highly symmetrical and each characterized by a single very narrow predominant peak. The adsorption-desorption of the hydrogen is coupled with the desorption-adsorption of the C1(-) ions. The results in this paper yield new insight as to the factors controlling hydrogen and anion electrosorption and demonstrate the importance of single crystal electrode studies under well defined conditions.