Abstract
Here, the concept of preferential leaching of cerium oxide on ternary Pt-C-CeO2 compound is demonstrated in order to develop a cost-effective catalyst for the cathode in proton exchange membrane fuel cells. The Pt-C-CeO2 thin film catalyst is prepared by simultaneous magnetron co-sputtering of Pt, C, and CeO2.
The morphology, structure, and composition of the Pt-C-CeO2 layer are characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Both half-cell and single-cell tests are performed to determine its activity and durability.
During an activation electrochemical cycling procedure, CeO2 is leached from the compound, leaving behind a porous Pt-C matrix which exhibits almost 3 times higher electrochemically active surface area in comparison with pure Pt with identical loading before and even after accelerated degradation tests in the half-cell. When used as the cathode in a single-cell membrane electrode assembly, decomposed Pt-C-CeO2 also shows greater power density than pure Pt.