PTFE/C三相电极氧阴极还原法生产过氧化氢

设计了隔膜体系电解槽,制作了聚四氟乙烯(PTFE)/碳黑三相气体扩散电极,系统研究了隔膜、电流密度、电极间距、初始溶液酸度、电解质、空气量和时间等因素对过氧化氢累积产生浓度和电流效率的影响。结果表明,在有隔膜体系,电流密度为70 mA/cm2,电极间距为1 cm,初始pH=0.5,电解质为0.10 mol/L Na2SO4溶液,空气量为40 mL/min的条件下,电解时间1 h时过氧化氢累积浓度最高可至20 096.05 mg/L,此时对应的电流效率为63.37%。在确定的最佳条件下,进行电解液循环实验,1 h时电流效率升高到98.4%,12 h之后,过氧化氢累积浓度为46 042.43 mg/L。实验原位产生的高浓度酸性过氧化氢溶液可以直接应用于Fenton试剂。

Production of hydrogen peroxide using three-phase electrode made of PTFE/C with oxygen-reduction

An electrolytic cell with a diaphragm system was designed. A three-phase gas diffusion electrode was prepared by PTFE and carbon black to study the effect of diaphragm, current density, electrode spacing, initial solution acidity, electrolyte, air volume and time on cumulative concentration of hydrogen peroxide and the current efficiency. For a diaphragm system, when current density is 70 mA/cm2, electrode spacing is 1cm, initial pH is 0.5, electrolyte is 0.10 mol/L Na2SO4 solution and air flow is 40 mL/min, the cumulative concentration of hydrogen peroxide could be up to 20 096.05 mg/L after 60 min, and the current efficiency is 63.37%. Under the optimum conditions, the current efficiency increases to 98.4% for 1 hour's cyclic electrolysis. After 12 hours, the cumulative concentration of hydrogen peroxide is 46 042.43 mg/L. The high concentration of acid hydrogen peroxide solution generated in situ can be directly used for Fenton reagent.