Nv. Vyazovikina et al., TEMPERATURE EFFECTS UPON KINETICS OF CHROMIUM ANODIC-DISSOLUTION IN ACIDIC SULFATE-SOLUTIONS, Russian journal of electrochemistry, 30(8), 1994, pp. 941-947
The influence of temperature (278 - 333 K) upon the kinetics of the an
odic dissolution of chromium was studied under nonstationary condition
s in acidic sulfate solutions. It was shown that at T greater than or
equal to 308 K and T less than or equal to 284 K the chronovoltammetri
c curves of monocrystal chromium of {100} crystallographic orientation
have one active region at the potentials -0.54 < E < -0.35 V and E >
-0.35 V, respectively. At higher temperatures (greater than or equal t
o 308 K) Cr dissolves mainly as Cr(II) ions and at lower temperatures
(less than or equal to 284 K), as Cr(III) ions. At temperatures betwee
n 289 and 303 K, the E vs. j-curves have two active regions at the neg
ative potentials, which correspond to the chromium dissolution with th
e commensurable rates as Cr(II) and Cr(III). An explanation of the exp
erimental results is given with an interpretation of the thermodynamic
and kinetic factors that are responsible for partial anodic processes
.