Seminar/ Colloquium

Title: Development of Fuel Cell Electrodes: Stabilization of Pt Catalyst with Anchoring Agents and Mitigation of Cobalt Dissolution

Speaker: Dr. Nagappan Ramaswamy General Motors Corporation, Global Fuel Cell Business, Pontiac, MI USA

Date: 5.30 – 6.30 PM (IST), March 17, 2023 (Friday) Hybrid Mode

Abstract: Proton Exchange Membrane (PEM) fuel cells are attractive alternatives for powering automotive applications for direct conversion of chemical energy stored in H2 fuel to electricity with high efficiency. They are widely considered to be the alternative for powering heavy-duty truck applications. While H2 oxidation on the anode of a fuel cell is kinetically fast, the O2 reduction reaction (ORR) occurring on the cathode is kinetically sluggish and imparts major efficiency losses. The current state of the art carbonsupported platinum (Pt/C) or platinum-cobalt (PtCo/C) based catalyst used for ORR are the most active materials, they face major durability challenges in fuel cell operating conditions. They primarily include the a) loss of electrochemically active surface area (ECSA) of Pt, and b) Co dissolution and contamination of the membrane of the fuel cell.

In this presentation, a few strategies for mitigating these two durability challenges will be discussed. These include a) system level operational strategies such as the use of lower relative humidity (RH), b) materials strategies such as the use of Pt-rich alloys (Pt5Co, Pt7Co) to mitigate Co dissolution, or c) the use of anchoring agents such as ZrO2 on the carbon support to mitigate Pt migration/coalescence. Recent successes in developing catalyst nanoparticles with a combination of better system-level and materials-level strategies will be discussed.