活性炭纤维电极产生过氧化氢的影响因素与机制研究

Electro-generation of hydrogen peroxide by an activated carbon fiber cathode: Influencing factors and mechanisms

以活性炭纤维为阴极、RuO2/Ti网为阳极、Na2SO4为支持电解质的电化学体系为研究对象,研究了电流强度、pH值和溶解氧含量等主要参数对电化学体系产生H2O2的影响.结果显示,在电流强度0.12～0.50 A范围内,H2O2的生成量随着电流强度增大而升高,反应60 min后,H2O2浓度可达稳定值;电化学体系具有较宽泛的pH范围,初始pH在2.0～6.0时活性炭纤维阴极产生的H2O2均高于500μmol.L-1,pH 2.0时H2O2生成量最大,可达575.8μmol.L-1;体系中溶解氧浓度影响H2O2的电化学生成量,溶解氧浓度越高H2O2生成量越大;无背景气体通入时,电化学体系自身产生的溶解氧可以支持活性炭纤维阴极产生高浓度的H2O2.研究结果表明具有高比表面积的活性炭纤维电极是一种高效的电-Fenton阴极.

Electro-generation of hydrogen peroxide （H202 ） was achieved in an electrochemical system with the activated carbon fiber （ACF） and RuO2/ Ti mesh as cathode and anode, respectively. Na2 SO4 solution was used as supporting electrolyte. The effects of current intensity, initial pH and the dissolved oxygen content on the H2 02 generation were investigated in details. Results indicated that the generated amount of H2O2 increased with the applied current ranging from 0.12 to 0.50 A, and remained nearly constant after 60 min. When pH ranged from 2.0 to 6.0, concentrations of the generated H2 02 were higher than 500μmol·L^-1 , with the maximum of 575.8 μmol·L^-1 when pH was 2. O. The production amount of H2O2 increased with the dissolved oxygen content. Without the addition of oxygen, high concentration of H2O2 was still generated by the dissolved oxygen at the anode. The above results suggested that the ACF electrode with a large surface area is a suitable cathode in the electro-Fenton process.