Fig. 3: Characteristics of the GDEs with PIMs as binders in the catalyst layer.

a Pore-size distributions of GDEs with various binders as indicated in the figure. b SBET of GDE of GDEs with different binders measured by N2 adsorption isotherm at 77 K. c The contact angle of the different GDEs with phosporic acid. The Pt/C GDE means refers to binderless electrodes. The content of the binder in the catalyst layer was 20 wt% of total solid in the catalyst ink.