| 摘要 |
PURPOSE:To enhance electrolytic current efficiency by preventing the rising in electrolytic voltage caused by gas bubbles generated at an electrode, in an electrolytic cell using an aqueous alkali metal salt solution according to a cation exchange membrane method, by constituting a cathode structure from a hydrogen generating electrode and a metal porous body. CONSTITUTION:An electrolytic cell for preparing Cl-gas and NaOH by electrolyzing an aqueous NaCl solution is set to one according to a cation exchange membrane system. The anode used in this electrolytic cell is brought into close contact with a cation exchange membrane and a cathode is arranged in a cathode chamber so as to leave the interval of 5mm. or less from the anode. The cathode is formed of a hydrogen generating cathode formed of an expanded metal or punching metal with an opening ratio of 10- 90% and an opening diameter of several mm.- several cm and a porous metal body made of stainless steel which is higher in hydrogen overvoltage than that of said hydrogen generating electrode, excellent in corrosion resistance to an alkaline solution and has filter effect. H2 generated at the cathode is smoothly excluded from the cathode surface and the rising in the electrolytic voltage of the electrolytic cell based on the presence of air bubbles is prevented. |
