MHD effect under the interaction of external magnetic field with electrolytic hydrogen and oxygen bubbles

V. N. Zaichenko - I. A. Slobodyanyuk - I. A. Rusetskii

V.I. Vernadskii Institute of General and Inorganic Chemistry of the Ukrainian NAS, 32/34 Palladina pr., 03680 Kyiv, Ukraine

Abstract
It is known that the action of an external steady magnetic field creates forced convection in electrolyte. During water electrolysis, the steady magnetic field reduces the overvoltage reactions of the hydrogen and oxygen evolution and enhances the process productivity. The obtained data indicate that in addition to the conductive influence of the steady field on the electrolyte, where an electric current passes, the same effect occurs for gas bubbles that are charged at the time they leave the electrodes. It is shown that hydrogen bubbles are negatively charged, and oxygen is positive in acidic and alkaline pH regions, as well as at the zero point at pH ∼ 2.5. Trajectories of the motion of bubbles in the initial period are close to parabola. This is due to the action of an orthogonally directed Lorentz force F_L and a buoyancy force F_A. The vertical run of the trajectories indicates that F_L → 0, which means that the charges on the bubbles disappear. It has been suggested that the negative charge on hydrogen bubbles is created by hydrated electrons emitted from the cathode, which quickly interact with other particles in the electrolyte solution. Figs 6, Refs 19.