The theoretical behaviors of tubular electrodes: from semi-infinite diffusion to bulk electrolysis

• Published in: Electrochimica acta Vol. 44; no. 13; pp. 2281 - 2286
• Main Authors: Wu, Yirong, Wang, Zhenghao
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.1999; Elsevier
• Subjects: Chemistry; Conversion efficiency; Distribution of current; Electrochemistry; Electrodes: preparations and properties; Exact sciences and technology; General and physical chemistry; Non-Levich approximation; Numerical simulation; Other electrodes; Tubular electrode; Distribution of current; Numerical simulation; Conversion efficiency; Non-Levich approximation; Tubular electrode; Theoretical study; Current distribution; Convection diffusion equation; Concentration distribution; Finite difference method
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/S0013-4686(98)00347-8

The convective–diffusion equation of the tubular electrode in a parabolic velocity profile was solved with an implicit finite-difference numerical method and the distributions of current and concentration were obtained when axial diffusion was neglected. Several factors affecting the electrochemical behaviors of the tubular electrode were analyzed, which were represented by a normalized parameter w=x e d/ u 0 r 0 2. The relationship of the radial distribution of concentration and w shows that when w>0.03, the diffusion layer reaches the center of the tube, which makes the semi-infinite boundary condition invalid. The change of the current distribution in the direction of flow with w illustrates that w should be less than 0.6 to cause electrolysis on the whole electrode. In order to obtain a high yield and conversion efficiency, w should be larger than 0.105 and less than 0.417.