Use of layered double hydroxides to improve the triple phase boundary in anion-exchange membrane fuel cells

作者：Miyazaki Kohei; Abe Takeshi; Nishio Koji; Nakanishi Haruyuki; Ogumi Zempachi^*

来源：Journal of Power Sources, 2010, 195(19): 6500-6503.

DOI：10.1016/j.jpowsour.2010.04.023

• Anion-exchange membrane fuel cells
• Layered double hydroxides
• Triple phase boundary
• Oxygen-reduction
• Ionomers

We propose a novel approach that uses a positively charged inorganic compound, layered double hydroxide (LDH), as an anion conductor in anion-exchange membrane fuel cells to improve the triple phase boundary (TPB) of catalyst layers. Pt/C catalyst layers with hydrothermally prepared Mg-Al- and Ni-Al-based LDHs (MgAl-LDH and NiAl-LDH, respectively) were constructed, and their oxygen-reduction currents were evaluated under the same conditions as in anion-exchange membrane fuel cells. Scanning electron microscopy and a surface-area analysis revealed that the two LDHs had almost the same surface-area, size, and hexagonal cylinder structure. In contrast, electrochemical measurements showed that MgAl-LDH improved the current densities while NiAl-LDH showed the same current densities as the catalyst layer with no LDHs. These results suggest that MgAl-LDH introduced OH(-)-conducting paths within the catalyst layers and effectively increased the TPB region in anion-exchange membrane fuel cells.

• 出版日期2010-10-1