An H2/O2 Proton Exchange Membrane Fuel Cell (PEMFC) is a clean, sustainable energy source, suitable for the operation of small electronic devices [ 1]. Among the many problems that still exist for PEMFCs, slow reactions at the cathode electrode and poor mass transport of protons and electrons reduce fuel cell performance by increasing activation overvoltage or activation loss [2]. This problem can, however, be resolved by increasing the operating temperature of the fuel cell [3], but only up to a certain temperature before deformation or degradation of the polymer components occurs. Therefore, reducing the activation surge for low-temperature fuel cell operation is still necessary when PEMFC components are made of polymer. For electrode layers consisting of a carbon black-supported catalyst that is prone to agglomeration, previous studies have demonstrated a significant decrease in the activation overvoltage forming the three-phase boundary (i.e., ionomer, catalyst, and gas) in the primary pores, or gaps between the carbon black particles in an agglomerate, and the secondary pores, or the gaps between the agglomerates, which can accelerate redox reactions in the electrodes, increase catalyst utilization and fuel cell performance [4-6]. It has been shown that ionomer molecules that can be found in the primary pores of carbon black particles (< 40 nm in diameter) should have a low molecular weight [7] or can be formed by polymerization of monomers present in the primary pores [8]. In contrast, ionomer molecules with molecular weights on the order of several hundred thousand grams per mole (e.g. Nafion) cannot penetrate the primary pores and remain only in the secondary pore......at the center of the paper ..... Systems Explained, John Wiley & Sons, England, 2003.[4] T. Nakajima, T. Tamaki, H. Ohashi, T. Yamaguchi, J. Electrochem. Soc. 160 (2013) F129−F134.[5] M. Uchida, Y. Fukuoka, Y. Sugawara, N. Eda, A. Ohta, J. Electrochem. Soc. 143 (1996) 2245-2252.[6] H. Mizuhata, S.-i. Nakao, T. Yamaguchi, J. Power Sources 138 (2004) 25-30.[7] W. Phompan, N. Hansupalak, J. Power Sources 196 (2011) 147-152.[8] M. Carmo, T. Roepke, C. Roth, AM dos Santos, JGR Poco, M. Linardi, J. Power Sources 191 (2009) 330−337.[9] M. Watanabe, M. Tomikawa, S. Motoo, Journal of Electroanalytical Chemistry 195 (1985) 81−93.[10] M. Uchida, Y. Aoyama, N. Eda, A. Ohta, J. Electrochem. Soc. 142 (1995) 4143−4149[11] U. Thanganathana, D. Dixon, SL Ghatty, R. Bobba, Int. J. Hydrogen Energy 37 (2012) 17810-17820.[12] J. Parrondo, F. Mijangos, B. Rambabu, J. Power Sources 195 (2010) 3977−3983.