Fuel cells are an energy conversion device that directly transform the chemical energy from fuel into electrical energy through electrochemical reactions. Proton exchange membrane fuel cells (PEMFCs) utilize hydrogen and air to power eco-friendly electric vehicles. Yet, significant technical obstacles, high cost, limited lifetime and insufficient power density limit their broad applications.
For commercialization of PEMFCs, advanced cathode catalysts are needed due to sluggish oxygen reduction reaction (ORR) kinetics at the cathode. A high overpotential (400 mV) is required to generate practical current density, leading to an open circuit voltage (OCV) significantly below the theoretical value of 1.23 V. Moreover, over 40% of the current cost of PEMFCs arises from Pt catalysts used for the ORR.
In our lab, we are focused towards innovating ultralow-platinum (Pt) and non-precious metal catalysts for PEMFC cathodes. This involves precise manipulation of the catalysts' nanoparticle size and nanostructure based on understanding of the oxygen reduction reaction and hydrogen oxidation reaction. Furthermore, we have engineered various carbon supports for cathode catalysts by increasing surface area, synthesizing porous structures and/or doping the supports with other elements (e.g. oxygen, nitrogen, sulfur, etc.). By continuing to develop both the catalyst and the carbon support, we aim to produce highly durable PEMFCs that can pave the road to wide commercialization.