ISSN:
1434-1948
Keywords:
Autocatalysis
;
Cyclic voltammetry
;
Nitric acid
;
Nitrogen oxides
;
Reduction mechanism
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
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.
Additional Material:
19 Ill.
Type of Medium:
Electronic Resource
Permalink
