Electrochemistry of active chromium, part III: Effects of temperature

Journal of the Serbian Chemical Society

Popić Jovan P.¹  Dražić Dragutin M.¹ 

[1] Institute of Chemistry, Technology and Metallurgy - Center for Electrochemistry, Njegoševa 12, P. O. Box 473, 11001 Belgrade, Serbia and Montenegro;

关键词: chromium;    anodic dissolution;    anomalous dissolution;    hydrogen evolution;    sulfuric acid;    effect of temperature;    energy of activation.;   

DOI  :  10.2298/JSC0311871P

来源: DOAJ

【 摘 要 】

It was shown that the temperature in the range 20 – 65 ºC has considerable effects on the electrochemical anodic dissolution of chromium in the active potential range as well as on the electrochemical hydrogen evolution reactions on bare and oxide covered chromium surfaces. Also, the chemical dissolution of chromium is strongly affected. The apparent energy of activation for anodic dissolution is 63.1 kJ mol-1, for hydrogen evolution on a bare Cr surface 19.5 kJ mol-1, for the same reaction on an oxide covered surface 44.0 kJ mol-1 and for the chemical ("anomalous") dissolution 66.9 kJ mol-1. The temperature dependences of the total corrosion rate, and the electrochemical corrosion rate alone, are presented in polynomial forms with the appropriate constants obtained by the best fit of the experimental data. For the hydrogen evolution reaction on both bare and oxide covered chromium, the Volmer-Heyrovsky reaction mechanism with the second step as rate determining was proposed.

【 授权许可】

Unknown