Performance of Non-Precious Metal Electrocatalysts in Proton-Exchange Membrane Fuel Cells: A Review

Polymer electrolyte membrane fuel cells (PEMFCs) are an important enabler of the nascent hydrogen economy. However, due to the reliance on precious metal catalysts like platinum, reducing the cost and broad penetration of PEMFCs beyond vehicle application remains a challenge. In this respect, alternative non-precious metal catalysts and other carbon-based catalysts remain the holy grail toward advanced low-cost PEMFC. This review summarizes recent progress along the development of non-precious catalysts and their performance under PEMFC operation. Critical factors such as the activity, stability, and durability of non-precious metal catalysts and their associated mechanisms including the paths leading to degradation are discussed. Ultimately, the review concludes by highlighting the impressive activity and potential of NPM catalysts and the areas of focus to enable the translation of non-precious catalysts to commercially viable PEMFC systems.