Effects of magnetic field Directed orthogonally to Surfaces on electrochemical processes

The study provides a model for the effect on electrochemical processes of a magnetic field that is directed perpendicular to a planar electrode surface. The analysis assumes the formation of a hydrodynamic boundary layer of the fluid motion that is generated above a semi-infinite electrode as a result of magnetic force action. For a uniform magnetic field, the model predicts the decrease of the diffusion boundary layer thickness upon increasing either the magnetic field strength, B, or the reagent bulk concentration, C, with the power dependence corresponding to (CB2/3)-B-4/3. The limiting current density, i(L), is formulated as i(L) approximate to 0.5 chi(1/3)(m)(mu(o)rho)(-1/3RD5/9)-D-5/3 nu(-2/9)nFC B-4/3 (2/3). This permits semiquantitative interpretation of the enhanced mass transfer at electrode surfaces for electrochemical reactions and predicts a magnetic field effect on mass transfer-limited heterogeneous reactions of magnetic species. The results imply that the perpendicular magnetic field will affect any mass transport limited transformation involving paramagnetic species at flat surfaces.