Cathodic Reactions Involved in Corrosion Processes Occurring in Concentrated Nitric Acid at 100 °C

作者：Fanny Balbaud, Gérard Sanchez, Gérard Santarini, Gérard Picard · 发表于：European Journal of Inorganic Chemistry · 年份：2000 · DOI：10.1002/(sici)1099-0682(200004)2000:4<665::aid-ejic665>3.0.co;2-n · 被引用次数：53 · 研究领域：Corrosion Behavior and Inhibition、Chemical and Physical Properties in Aqueous Solutions、Industrial Gas Emission Control

In order to explain and analyze the corrosion process of AISI 304 L stainless steel in the presence of nitric acid condensates, the reduction mechanism of nitric acid was studied on a platinum electrode in various nitric acid solutions (4 mol·L−1, 8 mol·L−1 and 12 mol·L−1) at 100 °C. Classical electrochemical techniques were used: cyclic voltammetry, chronoamperometry on a stationary electrode as well as on a rotating disk electrode. A reduction mechanism is proposed; this mechanism is autocatalytic and involves a charge-transfer step and a heterogeneous chemical reaction which regenerates the electroactive species at the electrode surface. The electroactive species is assumed to be nitrous acid which is a soluble species. The other compounds involved in the reduction mechanism are NO and NO2, which are supposed to be adsorbed. The nitric acid concentration influences the major product of the reduction process: NO for concentrations lower than 8 mol·L−1 and NO2 for higher concentrations.