Up Scaled Microfluidic Fuel Cells With Porous Flow Through Electrodes

Abstract

In this work, an experimental microfluidic fuel cell is presented with a novel upscaled porous electrode architecture that provides higher available surface area compared to conventional microfluidic fuel cells, providing the potential for higher overall power outputs. Our proofofconcept architecture is an upscaled flowthrough fuel cell with more than nine times the active electrode surface area of the flowthrough architecture first proposed by Kjeang et al. (2008, “A Microfluidic Fuel Cell With FlowThrough Porous Electrodes,â€‌ J. Am. Chem. Soc., 130, pp. 4000–4006). Formic acid and potassium permanganate were employed as the fuel and oxidant, respectively, both dissolved in a sulfuric acid electrolyte. Platinum black was employed as the catalyst for both anode and cathode, and the performances of carbonbased porous electrodes including cloth, fiber, and foam were compared to that of traditional Toray carbon paper (TGPH120). The effects of catalyst loading were investigated in a microfluidic fuel cell containing 80 pores per linear inch carbon foam electrodes. A discussion is also provided of current density normalization techniques via projected electrode surface area and electrode volume, the latter of which is a highly informative means for comparing flowthrough architectures.