TY - JOUR
T1 - Electrochemical study of the mechanism of formation of the surface alloy of aluminum-niobium in LiCl-KCl eutectic melt
AU - Mohamedi, M.
AU - Kawaguchi, N.
AU - Sato, Y.
AU - Yamamura, T.
N1 - Funding Information:
The authors are grateful to Dr. Gery Stafford for valuable discussions and constant interest in this work. One of the authors (M.M.) is gratefully indebted to the Japan Society for the Promotion of Science (JSPS) for the assistance of a post-doctoral fellowship.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1999/6/1
Y1 - 1999/6/1
N2 - This work aims to describe the reduction mechanism by which niobium-aluminum alloys are formed in LiCl-KCl eutectic melt. The electrochemical reduction of AlCl3 at an inert electrode such as tungsten and at a niobium electrode, and the electroreduction of AlCl3 and Nb3Cl8 simultaneously were investigated by cyclic voltammetry, convolution voltammetry and chronoamperometry. At a tungsten electrode, AlCl3 was reduced to metallic aluminum via a quasi-reversible process involving a three-electron process. At a niobium electrode, AlCl3 showed very complex behaviour: underpotential deposition of aluminum followed by formation of a surface alloy of aluminum-niobium occurring at 540 and 180 mV above the pure aluminum deposition potential, respectively. The electroreduction of AlCl3 and Nb3Cl8, both present in the LiCl-KCl, confirmed these observations. From chronoamperometric measurements it was suggested that the niobium electroactive species is not reduced to the metallic form until the co-deposition of aluminum begins.
AB - This work aims to describe the reduction mechanism by which niobium-aluminum alloys are formed in LiCl-KCl eutectic melt. The electrochemical reduction of AlCl3 at an inert electrode such as tungsten and at a niobium electrode, and the electroreduction of AlCl3 and Nb3Cl8 simultaneously were investigated by cyclic voltammetry, convolution voltammetry and chronoamperometry. At a tungsten electrode, AlCl3 was reduced to metallic aluminum via a quasi-reversible process involving a three-electron process. At a niobium electrode, AlCl3 showed very complex behaviour: underpotential deposition of aluminum followed by formation of a surface alloy of aluminum-niobium occurring at 540 and 180 mV above the pure aluminum deposition potential, respectively. The electroreduction of AlCl3 and Nb3Cl8, both present in the LiCl-KCl, confirmed these observations. From chronoamperometric measurements it was suggested that the niobium electroactive species is not reduced to the metallic form until the co-deposition of aluminum begins.
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U2 - 10.1016/S0925-8388(99)00020-1
DO - 10.1016/S0925-8388(99)00020-1
M3 - Article
AN - SCOPUS:0032661778
VL - 287
SP - 91
EP - 97
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
IS - 1-2
ER -