Rational design of efficient and durable Pt-based electrocatalysts for fuel cells
Proton exchange membrane fuel cells (PEMFCs) offer an attractive zero-emission power generation technology to realize a carbon-neutral future. However, the competitiveness of PEMFCs is severely constrained by the costly precious metal catalysts needed for the cathode oxygen reduction reaction (ORR). This thesis aims to address two critical challenges in ORR catalysts, activity and durability. To this end, we first developed a facile molecular surface modification approach using dimethylformamide to improve the microkinetics of the physisorption/desorption process in ORR, to achieve an unprecedented specific activity of 21.8 mA/cm2 in modified model PtCuNi catalyst. Next, by exploiting a unique design of jagged Pt nanowire catalysts, we developed a high-performance PEMFC using PtCo nanowire catalysts to realize an unprecedented mass activity of 1.06 A/mgPt, far surpassing the Department of Energy target. Lastly, exploiting a strong-metal-oxide binding effect, we further designed a unique ultrafine Pt nanocatalysts with embedded cobalt oxide to achieve superior power performance and life durability. These studies offer new perspectives on fuel cell catalyst design and hold significant promise to substantially reduce the lifetime adjusted cost for widespread adoption of PEMFCs in practical technologies.