摘要
This work is concentrated on elucidating the mechanism of the electric field enhanced water dissociation.
A simple model was established for the theoretical current-voltage characteristics in water dissociation process on a
bipolar membrane based on the existence of a depletion layer and Onsager's theory. Particular attention was given
to the influence of applied voltage on depletion thickness and the dissociation constant. The factors on the water
splitting process, such as water diffusivity, water content, ion exchange capacity, temperature, relative permittivity,
etc. Were adequately analysed based on the derived model equations and several suggestions were proposed for
decreasing the applied voltage in practical operation. The water dissociation tests were conducted and compared
with both the theoretical calculation and the measured current-voltage curves reported in the literature, which
showed a very good prediction to practical current-voltage behavior of a bipolar membrane at high current densities
when the splitting of water actually commenced.
This work is concentrated on elucidating the mechanism of the electric field enhanced water dissociation. A simple model was established for the theoretical current-voltage characteristics in water dissociation process on a bipolar membrane based on the existence of a depletion layer and Onsager's theory. Particular attention was given to the influence of applied voltage on depletion thickness and the dissociation constant. The factors on the water splitting process, such as water diffusivity, water content, ion exchange capacity, temperature, relative permittivity, etc. were adequately analysed based on the derived model equations and several suggestions were proposed for decreasing the applied voltage in practical operation. The water dissociation tests were conducted and compared with both the theoretical calculation and the measured current-voltage curves reported in the literature, which showed a very good prediction to practical current-voltage behavior of a bipolar membrane at high current densities when the splitting of water actually commenced.
基金
Supported by the National Natural Science Foundation of China (No. 29976040), the Natural Science Foundation of Anhui Province (No. 99045431) and Youth Foundation of USTC.
关键词
电场增强
双极膜
水解离
模型
电流电压表征
bipolar membrane, electric field, water dissociation, current-voltage characteristics
