45results about How to "Reduce oxygen evolution overpotential" patented technology

The invention relates to a mixed additive for electrolyzing alkaline etching waste fluid, and a method for preparing copper powder with the mixed additive. Every litre of the aqueous solution of the mixed additive comprises the following components of 10 mg to 40 mg of urea, 0 mg to 30 mg of sodium hexametaphosphate, 0 mg to 30 mg of dodecyl trimethyl ammonium chloride, 10 mg to 50 mg of citrate, 10 mg to 70 mg of methyl trioctyl ammonium chloride, and 10 mg to 30 mg of triethanolamine. The mixed additive is adopted for carrying out electrolysis copper deposition treatment on the alkaline etching waste fluid, superfine copper powder with high additional value can be prepared, and recycling of the etching fluid is realized. Because a chlorine inhibition and oxygen evolution electrode is adopted as the electrolysis anode, no chlorine is separated out in the process of electrolysis regeneration, and no damage is caused to the environment while beneficial reuse of the etching waste fluid is realized.

The invention discloses a complex alloy used for an anode plate for refining metallic copper by electrolysis and a preparation method thereof. The complex alloy consists of the following components byweight percent: 0.3-3% of tin, 0.03-0.1% of calcium or strontium, 0.005-0.08% of cobalt, 0.03-0.09% of rare earth metal and the balance of lead. The preparation method comprises the steps of: smelting and preparing tin and cobalt into preliminary alloy of tin and cobalt in a melting furnace according to weight percent for standby; putting the lead and the preliminary alloy of tin and cobalt intothe melting furnace for melting, and preserving heat after the temperature is raised to be 450-550 DEG C; adding the calcium or the strontium, and the rare earth metal into the lead liquid according to the weight percent and stirring, and applying a 5-36 V direct current potential difference between the fusant and the furnace during the stirring process; and standing for 30-40 minutes after the fusant is alloyed evenly, and removing oxidizing slag on the surface of the fusant, thus obtaining the complex alloy. The invention simplifies the process flow, reduces material consumption, improves corrosion resistance, and simultaneously reduces melting temperature and metallic lead pollution.

The invention provides a preparation method of an electro-catalytic moisture desorption oxygen desorption catalyst in a carbonate system, and belongs to the field of chemical oxidation and electro-catalytic moisture desorption oxygen desorption. Comprising the steps that a stainless steel material containing a nickel source, an iron source and a chromium source serves as a substrate, oil stains and oxides on the surface of the stainless steel material are removed, then the stainless steel material reacts in an alkaline solution containing a persulfate oxidizing agent at the temperature of 20-110 DEG C for 0.25-3 h, a product is taken out, washed to be clean and then subjected to vacuum drying, and the NiFeCr composite hydroxide oxygen evolution material with the nanosheet structure is obtained. The electrode can greatly reduce the oxygen evolution overpotential for catalyzing water decomposition in a carbonate system, a test result shows that the electrode treated by adopting a potassium persulfate oxidizing agent has excellent oxygen evolution catalytic performance, and the oxygen evolution overpotential is 263 mV and 384 mV respectively when the current density is 10 mA cm <-2 > and 100 mA cm <-2 > in 0.5 mol L <-1 > Na2CO3/NaHCO3. The stainless steel substrate used in the method is cheap and easy to obtain, the treatment method is simple and easy to operate, conditions are mild, and the method is suitable for large-scale production.

A nickel-metal hydride storage battery comprises a shell, an electrode and electrolyte, the electrode comprises a positive electrode plate, a negative electrode plate and a diaphragm, the electrode is completely immersed in the electrolyte, materials of the positive electrode plate comprise a positive active material, a positive conductive agent, a positive additive and a positive adhesive, the positive active material comprises nickel hydroxide, the positive conductive agent comprises cobalt or nickel, the positive electrode additive comprises calcium hydroxide or zinc oxide, the positive electrode plate adhesive comprises carboxymethyl cellulose or polytetrafluoroethylene, the negative electrode plate is prepared from hydrogen storage alloy powder, a negative electrode conductive agent, a negative electrode additive and a negative electrode adhesive, the negative electrode conductive agent comprises conductive carbon or nickel powder, the negative electrode additive comprises zinc oxide or aluminum oxide, the negative electrode adhesive comprises hydroxypropyl methyl cellulose and butadiene styrene rubber, lining plates are arranged on the outer sides of the positive electrode plate and the negative electrode plate respectively, the lining plates are made of elastic materials, and a plurality of through holes are further formed in the lining plates. The invention provides a novel nickel-metal hydride storage battery which is safe, reliable, environment-friendly, pollution-free, long in service life, good in wide-temperature performance and large in capacity ratio.

The invention relates to a method for pretreating a lead base inert anode for electro-deposit copper. A pretreatment solution comprises cobaltous sulfate, sulfuric acid and distilled water, wherein the temperature of the pretreatment solution is 30-70 DEG C; the anode is to be pretreated, a cathode is a stainless steel plate, space between the anode and the cathode is 3-6cm, the circulating quantity of the pretreatment solution is 0.05-0.5V groove/h, V groove represents the volume of a pretreatment groove; and the pretreatment process is as follows: the current density of the anode is 50-400A/m<2>, and the pretreatment time is 8-24h. By adopting the pretreatment solution containing the cobaltous sulfate, parameters of the pretreatment process are optimized. The pretreatment process is simple, is convenient for operation, is beneficial to industrial application, and can be used for controlling oxygen evolution overpotential of the lead or lead alloy inert anode for the electro-deposit copper to be within 550mV. The lead or lead base anode treated by adopting the method is used as an anode for the electro-deposit copper, and remarkable effects are obtained on the aspects of reducing the content of lead as impurity of the cathode copper and reducing electricity consumption per ton of copper.