| 摘要 |
A cell is used contg. a membrane sepg. an anode chamber from a cathode chamber, in which a porous cathode is located. The cathode is a carbon or graphite felt or fabric, which is given a hydrophilic treatment prior to its use as the cathode. An emulsion of O2 or a gas contg. O2 in an aq. soln. of alkali hydroxide is fed through the cathode to formH202 dissolved in the soln. The hydrophilic treatment pref. consists in immersing the felt or fabric in (A) an alkanol, esp. pure, boiling ethanol for 2 h, then washing in water; or (B) in a hot mixt. of 50% chromic and sulphuric acids for 0.5-5 minutes, then washing in water. The pref. cell uses a perforated sheet anode made of Ni or steel coated with Ni. The prod. is an oxidising and bleaching agent which does not cause the corrosion and pollution created by similar agents based on Cl cpds., and can be used for bleaching paper pulp. |
