Optimizing Catalyst Loading Ratio between the Anode and Cathode for Ultralow Catalyst Usage in Polymer Electrolyte Membrane Fuel Cell

Abstract

With increasing demand for high-efficiency and clean energy sources, the polymer electrolyte membrane fuel cell (PEMFC) has received attention in a wide range of fields including transportation and back-up power. For securing the economic viability of PEMFC, the U.S. Department of Energy (DOE) provides the target of the total Pt catalyst loading as 0.125 mg Pt cm À2 on both cathode and anode, which is much less than that currently used (>0.25 mg Pt cm À2 for cathode). An optimized ratio of catalyst loading between the anode and cathode with a fixed Pt catalyst loading according to the DOE target is figured out by conducting diverse electrochemical measurements with varying the catalyst loading ratio in single-cells. Among the experimental set, the membrane electrode assembly (MEA) with 70% catalyst loading on the cathode side shows the highest performance with the maximum power density of 643 mW cm À2 , while the MEA with 90% catalyst loading on the cathode side exhibits inferior performance. Experimental results are validated by suggesting the theoretical model, which was established based on considering both the electrochemical kinetics of hydrogen oxidation and oxygen reduction reaction.

(Digital Presentation) Synthesis of Proton Exchange Membrane Fuel Cell Catalyst and Optimization of Membrane Electrode Assembly Preparation Parameters

“…The ECA values of the electrodes at different catalyst loadings are shown in Figure3b. It shows that the ECA (m Pt 2 ) depends linearly on the catalyst loading -this is in an agreement with the literature(18).…”

Multiscale Architectured Membranes, Electrodes, and Transport Layers for Next‐Generation Polymer Electrolyte Membrane Fuel Cells

“…The governing equation for the operating cell voltage is expressed as follows: [ 2,39 ] $$\[{E_{{\rm{cell}}}} = {E_{{\rm{rev}}}} - {\eta _{{\rm{kinetic}}}} - {\eta _{{\rm{ohmic}}}} - {\eta _{{\rm{mass}}}}\]$$where E cell is the operating cell voltage, E rev is the reversible voltage, η kinetic is the kinetic overpotential, η ohmic is the Ohmic overpotential, and η mass is the mass‐transport (concentration) overpotential. The kinetic overpotential, η kinetic , can be expressed as a function of L c : [ 40,41 ] $$\[{\eta _{{\rm{kinetic}}}} = \left( {\frac{{RT}}{{\alpha nF}}} \right)\ln \frac{j}{{{j_0}}} = \left( {\frac{{RT}}{{\alpha nF}}} \right)\ln \frac{j}{{{L_C}j_0^,}}\]$$where R is the gas constant, T is the operational temperature, α is the transfer coefficient, n is the number of electrons participating in the electrochemical reaction, F is Faraday's constant, j is the current density during operation, j 0 is the exchange current density (A cm −2 ), $$j_0^,$$ is the catalyst‐specific exchange current density (A g −1 ), and L C is the effective catalyst loading per unit area (g cm −2 ). In this equation, high values of $$j_0^,$$ and α indicate that the reaction can be easily initiated by decreasing η kinetic .…”

“…where E cell is the operating cell voltage, E rev is the reversible voltage, η kinetic is the kinetic overpotential, η ohmic is the Ohmic overpotential, and η mass is the mass-transport (concentration) overpotential. The kinetic overpotential, η kinetic , can be expressed as a function of L c : [40,41] ln ln kinetic 0 0 , RT nF…”

Influence of Fe–N–C morphologies on the oxygen reduction reaction in acidic and alkaline media

“…The US Department of Energy (DOE) has set the goal of developing more cost‐effective and efficient PGM electrocatalysts for fuel cells 9 . Various approaches have been applied to find the best Fe–N–C catalyst to achieve the desired performance as required by the DOE, such as controlling the morphology of the catalyst 10 .…”

“…7,8 The United States Department of Energy (DOE) has set the goal of developing more cost-effective and efficient PGM electrocatalysts for fuel cells. 9 Various approaches have been applied to find the best Fe-N-C catalyst to achieve the desired performance as required by the DOE, such as controlling the morphology of the catalyst. 10 By controlling the morphology of Fe-N-C electrocatalysts, it is possible to achieve better performance, stability, and mass transport, which can lead to more efficient and durable fuel cells.…”