Oxygen reduction on Teflon-bonded carbon gas diffusion electrode without cataly st in 6 mol/L KOH solution was investigated with acimpedance spectroscopy and o ther electrochemical techniques. The kinetic parameters w...Oxygen reduction on Teflon-bonded carbon gas diffusion electrode without cataly st in 6 mol/L KOH solution was investigated with acimpedance spectroscopy and o ther electrochemical techniques. The kinetic parameters were measured with an ex change current density of J0=3.44×10-9 and a Tafel slope of 46 mV/ dec in low overpotential range （-0.05-0.14 V vs SCE）,which are compara ble with those reported on carbon supported platinum electrode. The reaction mec hanism of OR and the active effect of carbon black were examined.展开更多
Oxygen reduction(OR)on Teflon-bonded carbon electrodes with manganese oxide as catalyst in 6 mol/L KOH solution was investigated using AC impedance spectroscopy combined with other techniques. For OR at this electrode...Oxygen reduction(OR)on Teflon-bonded carbon electrodes with manganese oxide as catalyst in 6 mol/L KOH solution was investigated using AC impedance spectroscopy combined with other techniques. For OR at this electrode, the Tafel slope is –0.084 V/dec and the apparent exchange current density is (1.02-3.0)×10-7 A/cm2. In the presence of manganese oxide on carbon electrode, the couple Mn3+/Mn4+ reacts with the O2 adsorbed on carbon sites forming O ?2 radicals and acceletes the dismutation of O 2?, which contributes to the catalytic effect of manganese oxide for OR reaction.展开更多
A study on the electrochemical disinfection with H202 generated at the gas diffusion electrode （GDE） from active carbon/poly- tetrafluoroethylene was performed in a non-membrane cell. The effects of Pt load and the ...A study on the electrochemical disinfection with H202 generated at the gas diffusion electrode （GDE） from active carbon/poly- tetrafluoroethylene was performed in a non-membrane cell. The effects of Pt load and the pore-forming agent content in GDE, and operating conditions were investigated. The experimental results showed that nearly all bacterial cultures inoculated in the secondary effluent from wastewater treatment plant could be inactivated within 30 min at a current density of 10 mA/cm^2. The disinfection improved with increasing Pt load. Addition of the pore-forming agent NH4HCO3 improved the disinfection, while a drop in the pH value resulted in a rapid rise of germicidal efficacy and the disinfection time was shortened with increasing oxygen flow rate. Adsorption was proved to be ineffective in destroying bacteria, while germicidal efficacy increased with current density. The acceleration rate was different, it initially increased with current density. Then decreased, and finally reached a maximum at a current density of 6.7 mA/cm^2. The disinfection also improved with decreasing total bacterial count. The germicidal efficacy in the cathode compartment was approximately the same as in the anode compartment, indicating that the contribution of direct oxidation and the indirect treatment of bacterial cultures by hydroxyl radical was similar to the oxidative indirect effect of the generated H2O2.展开更多
In recent years, as one of the most promising chemical power sources for future society, lithium–oxygen (Li–O2) battery receives great attention due to its extremely high theoretical energy density of 3505 Wh kg^(–...In recent years, as one of the most promising chemical power sources for future society, lithium–oxygen (Li–O2) battery receives great attention due to its extremely high theoretical energy density of 3505 Wh kg^(–1)[1–4]. In practice, large polarization and consequent low energy efficiency currently still hinder the application of Li–O2batteries, which mainly results from the sluggish electrochemical reaction kinetics of oxygen diffusion electrodes in aprotic electrolytes [5]. On one hand, oxygen reduction reaction (ORR)in aprotic electrolytes is intrinsically sluggish due to the difficult charge transfer, the low solubility of oxygen.展开更多
文摘Oxygen reduction on Teflon-bonded carbon gas diffusion electrode without cataly st in 6 mol/L KOH solution was investigated with acimpedance spectroscopy and o ther electrochemical techniques. The kinetic parameters were measured with an ex change current density of J0=3.44×10-9 and a Tafel slope of 46 mV/ dec in low overpotential range （-0.05-0.14 V vs SCE）,which are compara ble with those reported on carbon supported platinum electrode. The reaction mec hanism of OR and the active effect of carbon black were examined.
基金Project(1766-394201123) supported by the Natural Science Foundation of Hunan Province, China
文摘Oxygen reduction(OR)on Teflon-bonded carbon electrodes with manganese oxide as catalyst in 6 mol/L KOH solution was investigated using AC impedance spectroscopy combined with other techniques. For OR at this electrode, the Tafel slope is –0.084 V/dec and the apparent exchange current density is (1.02-3.0)×10-7 A/cm2. In the presence of manganese oxide on carbon electrode, the couple Mn3+/Mn4+ reacts with the O2 adsorbed on carbon sites forming O ?2 radicals and acceletes the dismutation of O 2?, which contributes to the catalytic effect of manganese oxide for OR reaction.
基金supported by the National Natural Science Foundation of China (No.20777053)
文摘A study on the electrochemical disinfection with H202 generated at the gas diffusion electrode （GDE） from active carbon/poly- tetrafluoroethylene was performed in a non-membrane cell. The effects of Pt load and the pore-forming agent content in GDE, and operating conditions were investigated. The experimental results showed that nearly all bacterial cultures inoculated in the secondary effluent from wastewater treatment plant could be inactivated within 30 min at a current density of 10 mA/cm^2. The disinfection improved with increasing Pt load. Addition of the pore-forming agent NH4HCO3 improved the disinfection, while a drop in the pH value resulted in a rapid rise of germicidal efficacy and the disinfection time was shortened with increasing oxygen flow rate. Adsorption was proved to be ineffective in destroying bacteria, while germicidal efficacy increased with current density. The acceleration rate was different, it initially increased with current density. Then decreased, and finally reached a maximum at a current density of 6.7 mA/cm^2. The disinfection also improved with decreasing total bacterial count. The germicidal efficacy in the cathode compartment was approximately the same as in the anode compartment, indicating that the contribution of direct oxidation and the indirect treatment of bacterial cultures by hydroxyl radical was similar to the oxidative indirect effect of the generated H2O2.
基金supported by grants from the National Natural Science Foundation of China (Nos. 21673169, 51672205, 51972257)the National Key Research Program of China (No. 2016YFA0202602)+1 种基金the Research Start-Up Fund from Wuhan University of Technologythe Fundamental Research Funds for the Central Universities (WUT: No. 2019IB003)。
文摘In recent years, as one of the most promising chemical power sources for future society, lithium–oxygen (Li–O2) battery receives great attention due to its extremely high theoretical energy density of 3505 Wh kg^(–1)[1–4]. In practice, large polarization and consequent low energy efficiency currently still hinder the application of Li–O2batteries, which mainly results from the sluggish electrochemical reaction kinetics of oxygen diffusion electrodes in aprotic electrolytes [5]. On one hand, oxygen reduction reaction (ORR)in aprotic electrolytes is intrinsically sluggish due to the difficult charge transfer, the low solubility of oxygen.
