HYDROGEN EVOLUTION, HYDRIDE FORMATION, AND DISSOLUTION OF MAGNESIUM IN THE PRESENCE OF COMPLEXING REAGENTS

The effect of potential and complexing reagents on magnesium dissoluti on, hydrogen evolution, and hydride formation on a magnesium anode in a chloride solution has been studied. When soluble magnesium complexes are formed, the surface locally activated by chloride can pass to a u niformly passive state, and the more stable the complex, the more effi cient the passivation. Passivation hinders the discharge of hydrogen, hydride formation, and the corresponding ''self-dissolution'' of the a node. The latter process can slow down by a factor of 28 - 30, while t he efficiency of metal utilization can increase from 23 to 91%. Comple x formation suppresses the hydrolysis of Mg2+ ions and the acidificati on of the near-electrode electrolyte, but protonated ligands acting as weak acids can activate the anode, thus favoring the adsorption of hy droxonium ions, which participate in hydride formation and metal self- dissolution, on the anode.