caa a22 4500 475815629 CHVBK 20180406123809.0 cr unu---uuuuu 170329e20001001xx s 000 0 eng 10.1023/A:1004052419708 doi (NATIONALLICENCE)springer-10.1023/A:1004052419708 Electrochemical synthesis of Cr(II) at carbon electrodes in acidic aqueous solutions [Elektronische Daten] [Q. Yin, N.P. Brandon, G.H. Kelsall] The electrochemical synthesis of Cr(II) has been investigated on a vitreous carbon rotating disc electrode and a graphite felt electrode using cyclic voltammetry, impedance spectroscopy and chronoamperometry. The results show that in 0.1 M Cr(III) + 0.5 M sulphuric acid and in 0.1 M Cr(III) + 1 M hydrochloric acid over an electrode potential range of −0.8 to 0.8 V vs SCE, the electrochemical reaction at carbon electrodes is essentially a surface process of proton adsorption and desorption, without significant hydrogen evolution and chromium(II) formation. At electrode potentials more negative than −0.8 V vs SCE, both hydrogen evolution and chromium(II) formation occurred simultaneously. At electrode potentials −0.8 to −1.2 V vs SCE, the electrochemical reduction of Cr(III) on carbon electrodes is controlled mainly by charge transfer rather than mass transport. Measurements on vitreous carbon and graphite felt electrodes in 1 M HCl, with and without 0.1 M CrCl3, allowed the exchange current density and Tafel slope for hydrogen evolution, and for the reduction of Cr(III) to Cr(II), to be determined. The chromium(III) reduction on vitreous carbon and graphite electrodes can be predicted by the extended high field approximation of the Butler-Volmer equation, with a term reflecting the conversion rate of Cr(III) to Cr(II). Kluwer Academic Publishers, 2000 carbon electrode nationallicence chromium (III)/(II) nationallicence electrochemical synthesis nationallicence electrochemistry nationallicence Yin Q. T.H. Huxley School of Environment, Earth Science and Engineering, Imperial College of Science, Technology and Medicine, SW7 2BP, London, Great Britain aut Brandon N.P. T.H. Huxley School of Environment, Earth Science and Engineering, Imperial College of Science, Technology and Medicine, SW7 2BP, London, Great Britain aut Kelsall G.H. T.H. Huxley School of Environment, Earth Science and Engineering, Imperial College of Science, Technology and Medicine, SW7 2BP, London, Great Britain aut Journal of Applied Electrochemistry Kluwer Academic Publishers 30/10(2000-10-01), 1109-1117 0021-891X 30:10<1109 2000 30 10800 https://doi.org/10.1023/A:1004052419708 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1004052419708 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yin Q. T.H. Huxley School of Environment, Earth Science and Engineering, Imperial College of Science, Technology and Medicine, SW7 2BP, London, Great Britain aut NATIONALLICENCE 700 1- Brandon N.P. T.H. Huxley School of Environment, Earth Science and Engineering, Imperial College of Science, Technology and Medicine, SW7 2BP, London, Great Britain aut NATIONALLICENCE 700 1- Kelsall G.H. T.H. Huxley School of Environment, Earth Science and Engineering, Imperial College of Science, Technology and Medicine, SW7 2BP, London, Great Britain aut NATIONALLICENCE 773 0- Journal of Applied Electrochemistry Kluwer Academic Publishers 30/10(2000-10-01), 1109-1117 0021-891X 30:10<1109 2000 30 10800 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer