Abstract: STUDY OF REDUCTION MECHANISM OF NITRIC ACID ON INERT PLATINUM CATHODEYe Guoan He Jianyu(China Institute of Atomic Energy,P.O.Box275 (26),Beijing 102413)ABSTRACTThe electrolytic reduction of nitric acid on inert platinum cathode at room temperature with potentiostatic method is investigated. The cathodic polarized curve is recorded and the reduction products is determined. The dependence of reduction products on cathodic potential is revealed and the autocatalytical nature of cathodic process of HNO3 is elucidated through the experiment results. The catalytical role of HNO2 is elucidated, and the mechanism of direct reduction of moderate concentrated HNO3 is demonstrated,in terms of the spectra phenomena of NO－2 and NO－3 in acidic solutions.Key words Nitric acid Nitrous acid Electrolytic reduction Reduction chain Autocatalysis Inert platinum cathode