The catalytic activity of cysteine and cystine on the electroreduction of Bi(III) ions

The catalytic influence of cysteine and cystine on mechanism and kinetics of Bi(III) electroreduction in chlorates (VII) solutions was studied. The kinetic parameters determined by using of electrochemical techniques pointed at the magnitude of catalytic effect of cysteine and cystine and allowed to achieve the mutual correlation of these values. It was found that the catalytic effect of cysteine and cystine is the biggest in 3 mol dm−3 chlorates (VII) and that the increase of Bi(III) ions electroreduction process rate in 3 mol dm−3 chlorates (VII) solutions is much bigger in the presence of cysteine comparing to cystine.

► The cysteine and cystine influence the rate of Bi(III) electroreduction in 3 mol dm−3 chlorate (VII).
► Cysteine is a stronger catalyst of Bi(III) ions electroreduction on mercury in 3 mol dm−3 chlorate (VII).
► Catalytic effect is connected with the equilibrium of active complexes formation mediating in electron transfer.