ELECTROCHEMICAL STUDY OF DIRECT AND INDIRECT NO REDUCTION WITH COMPLEXING AGENTS AND REDOX MEDIATOR

A high degree of NO conversion was achieved using Fe-II(EDTA) as a com plexing agent and dithionite S2O42- as redox mediator. The details of NO absorption solution as well as the kinetics of electrochemical dith ionite regeneration are reported. In addition the complex polarisation behaviour of Fe-II(EDTA) was studied. The overall electrode process i ncludes the Fe-II<->Fe-III charge transfer, the proton reduction, the cathodic deposition of iron, and the anodic EDTA decomposition. Distin ctive cathodic currents were determined in the Fe-II(EDTA)NO solutions which are indicative of NO reduction. The results obtained show the p ossibility of direct electrochemical NO conversion on electrodes. (C) 1997 Published by Elsevier Science Ltd.