高效产H2O2气体扩散电极的研究

High-efficienty gas diffusion electrode for the generation of hydrogen peroxide

采用C/PTFE气体扩散电极在无隔膜体系中进行H2O2发生工艺研究,探讨了石墨和Vulcan XC-72碳黑两种碳材料以及电解电压、p H值对该反应过程的影响.结果表明,在较低的空气流量(1.41 cm3·min-1·cm-2)下,以Vulcan XC-72碳黑为表面的气体扩散电极相比石墨电极有较高的H2O2产率和电流效率,碱性条件比酸性条件下H2O2产率和电流效率更好;在2.6 V恒定电压下,2 h后,H2O2浓度达到了250 mg·L-1,电流效率从69.8%降到44.7%,单位产量能耗从5.87 k Wh·kg-1升高到9.16 k Wh·kg-1.

This study focused on the preparation of C/PTFE gas diffusion electrode and their use for generating hydrogen peroxide in an undivided system. The technique character is that the process could maintain high hydrogen peroxide generation rate, high current efficiency and reasonable energy consumption on the lower aeration rate. The experimental results demonstrated that factors including the carbon species （ graphite or Vulcan XC-72） , voltage and pH showed apparent influences on the hydrogen peroxide generation. The gas diffusion electrode made of Vulcan XC-72 showed higher hydrogen peroxide generation rate and current efficiency than the GDE made of graphite. And it was also observed that the alkaline pH was beneficial to the hydrogen peroxide generation. The hydrogen peroxide concentration reached 250 mg·L^-1 after 2 h, and current efficiency declined from 69.8% to 44.7%, while energy consumption increased from 5. 87 kWh·kg^-1 to 9. 16 kWh·kg^-1 , when the aeration rate was 1.41 cm^3·min^-1·cm^-2 , and the voltage was 2.6 V.