Mass transportation in diethylmethylammonium trifluoromethanesulfonate for fuel cell applications |
| |
Authors: | Shigenori Mitsushima Yoshitsugu Shinohara Koichi Matsuzawa Ken-ichiro Ota |
| |
Affiliation: | Chemical Energy Laboratory, Yokohama National University, Yokohama 240-8501, Japan |
| |
Abstract: | To use the protonic mesothermal fuel cell without humidification, mass transportation in diethylmethylammonium trifluoromethanesulfonate (dema]TfO]), trifluoromethanesulfuric acid (TfOH)-added dema]TfO], and phosphoric acid (H3PO4)-added dema]TfO] was investigated by electrochemical measurements. The diffusion coefficient and the solubility of oxygen were ca. 10−5 cm2 s−1 and ca. 10−3 M (=mol dm−3), respectively. Those of hydrogen were a factor of 10 and one-tenth compared to oxygen, respectively. The permeability, which is a product of the diffusion coefficient and solubility, of oxygen and hydrogen were almost the same for the perfluoroethylenesulfuric acid membrane and the sulfuric acid solution; therefore, these values are suitable for fuel cell applications. On the other hand, a diffusion limiting current was observed for the hydrogen evolution reaction. The current corresponded to ca. 10−10 mol cm−1 s−1 of the permeability, and the diffusion limiting species was the hydrogen carrier species. The TfOH addition enhanced the diffusion limiting current of dema]TfO], and the H3PO4 addition eliminated the diffusion limit. The hydrogen bonds of H3PO4 or water-added H3PO4 might significantly enhance the transport of the hydrogen carrier species. Therefore, dema]TfO] based materials are candidates for non-humidified mesothermal fuel cell electrolytes. |
| |
Keywords: | Room temperature molten salts Fuel cells Mass transport Mesothermal |
本文献已被 ScienceDirect 等数据库收录! |
|