Strategies for Reducing the PGM Loading in High Power AEMFC Anodes

Travis J Omasta,Andrew M Park,Bryan Pivovar,John R Varcoe,Xiong Peng,Yufeng Zhang,William E Mustain

doi:10.1149/2.1401809jes

Abstract

Anion Exchange Membrane Fuel Cells (AEMFCs) have experienced a significant rise in attention in recent years, largely motivated by the potential to overcome the costs that have plateaued for proton exchange membrane fuel cells. However, despite significant advances in power generation, membrane conductivity, membrane stability, and catalyst activity, the vast majority of high performing AEMFCs are fabricated with a high PGM loading (0.4–0.8 mg cm−2). This work demonstrates an electrode fabrication method that reduces the anode catalyst loading by 85% while still achieving performance ca. 1 W cm−2 – accomplished by designing a multi-layered electrode comprised of an optimized ionomer:carbon:PGM ratio catalyst layer coupled with a hydrophobic microporous layer. If paired with a high-performing PGM-free cathode, this new anode shows the potential to meet existing DOE PGM loading and performance targets.

Highlights

In order to reduce the platinum group metal (PGM) loading in operating Anion Exchange Membrane Fuel Cells (AEMFCs), there will need to be at least some development of non-PGM catalysts
In order to reduce the PGM loading in operating AEMFCs, there will need to be at least some development of non-PGM catalysts
At the AEMFC anode, it is very likely that it will be difficult to move completely away from PGM-based catalysts, though this is presently an active area for research.[24,25]. It is important for researchers in the field to investigate electrode compositions that allow for reduced catalyst loading – the most active hydrogen evolution catalyst known today is PtRu26 – while still allowing for the water produced during the hydrogen oxidation to be properly managed, a crucial step in the successful operation of AEMFCs.[3,14,15]

Summary

Introduction

In order to reduce the PGM loading in operating AEMFCs, there will need to be at least some development of non-PGM catalysts. Some very promising catalysts have already been identified.[3,18,19,20,21,22,23] at the AEMFC anode, it is very likely (akin to the PEMFC cathode) that it will be difficult to move completely away from PGM-based catalysts, though this is presently an active area for research.[24,25] it is important for researchers in the field to investigate electrode compositions that allow for reduced catalyst loading – the most active hydrogen evolution catalyst known today is PtRu26 – while still allowing for the water produced during the hydrogen oxidation to be properly managed, a crucial step in the successful operation of AEMFCs.[3,14,15] Properties of the catalyst layer such as structure, thickness, porosity, component chemistry, and. The peroxidated ETFE films act as a solid-state free-radical initiator for the subsequent grafting step. The resulting intermediate ETFE-g-poly(VBC) films were subsequently dried at 70◦C for 5 h in a vacuum oven to remove all traces of solvent

Objectives

Results

Conclusion