气调保鲜技术因不使用防腐剂、健康、环保而备受市场青睐。电化学控氧技术利用氧还原反应控制密闭空间中的氧含量，无噪音、长效安全，是家电冰箱气调保鲜的首选技术之一。电化学控氧核心是用于支撑氧还原反应的气体扩散电极，但其存在低温催化效率低、电极极化大、长期使用易渗漏等问题，严重阻碍家电领域的实用化。针对这些问题，本文通过催化剂制备、电极材料选择与成型工艺调整等，对气体扩散电极的制备工艺进行了优化，结合控氧模块的工业化设计，有效提升电极的电化学性能和使用寿命，实现了模块的长期控氧保鲜效果。

采用热分解法制备Ag/C催化剂，结果表明金属态Ag负载在活性炭上，部分Ag原子通过O-C共价结合。17% Ag/C催化剂的粒子均匀性较好、导电性佳，具有最佳的氧还原催化性能。采用该催化剂制备的气体扩散电极，在催化层中的质量份数为45时，催化氧还原性能最佳。在优化催化剂及催化层的基础上，当防水透气层组成为100份聚四氟乙烯（PTFE）乳液#1、30 ~ 50份活性炭#1、10 ~ 20份乙炔黑#1时，以辊压-烧结工艺制备的膜层中PTFE呈纤维状，均匀包覆在活性炭表面。同时电极催化活性最高，可在1.078 V工作电压200 mA/cm²电流运行。

由前述工艺制得电极模块，装配电化学控氧单元、模拟果蔬盒，可在22.5 A（50 mA/cm²）的恒电流下，实现80.1 mL/min的氧气转换率，在23 min内将30 L果蔬盒内的氧气浓度控制在15%以下，符合商业化控氧保鲜的技术要求。经某大型家电企业产业化装配测试，控氧单元可实现恒流80 mA/cm²下2000 h以上的长效运行。

Controlled atmosphere preservation technology is favored by the market because it does not use preservatives, health and environmentally friendly. Oxygen reduction reaction (ORR) is used in electrochemical oxygen control technology to control the oxygen content in confined space. The technology has no noise, long-term safety, and is one of the preferred technologies for controlled atmosphere preservation of household appliance refrigerators. Gas diffusion electrode (GDE), which is the core of electrochemical oxygen control, is used to support ORR. However it has some problems, such as low catalytic efficiency at low temperature, large electrode polarization, and easy leakage after long-term use, which seriously hinders the practical application in the field of household appliances. To solve thses problem, the preparation process of GDE is optimized through catalyst preparation, electrode material selection and molding process adjustment. Combined with the industrial design of oxygen control module, the electrochemical performance and service life of the electrode are effectively improved, and the long-term oxygen control and fresh-keeping effect of the module is realized.

Ag/C catalyst was prepared by thermal decomposition method. The results showed that metallic AG was supported on activated carbon, and some Ag atoms were covalently bound by O-C. 17% Ag/C catalyst has good dispersion and conductivity, and has the best catalytic performance for oxygen reduction. The GDE prepared with the catalyst has the best catalytic oxygen reduction performance when the mass fraction in the catalytic layer is 45. On the basis of optimizing the catalyst and catalyst layer, when the waterproof and breathable layer is made up of mass fraction of 100 polytetrafluoroethylene (PTFE) emulsion #1, 30 ~ 50 activated carbon #1 and 10 ~ 20 acetylene black #1, the PTFE in the film prepared by rolling sintering process is fibrous and uniformly coated on the surface of activated carbon. At the same time, the electrode has the highest catalytic activity and can operate at a working voltage of 1.078 V and a current of 200 mA/cm².

The electrode module is prepared by the above process, and an electrochemical oxygen control unit and a simulated fruit and vegetable box are assembled. The oxygen conversion rate of 80.1 mL/min can be achieved under the constant current of 22.5 A (50 mA/cm²), and the oxygen concentration in 30 L fruit and vegetable boxes can be controlled below 15% within 23 min, meeting the technical requirements for commercial oxygen control and preservation. After the industrial assembly test of a large household electrical appliance enterprise, the oxygen control unit can achieve long-term operation of more than 2000 h under the constant current of 80 mA/cm².

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