Rhodium nanostructured thin film catalysts were prepared by pulsed laser deposition. The depositions were performed under vacuum and at different He background gas pressures ranging from 1 to 5 Torr. SEM, TEM, X-ray diffraction, and X-ray photoelectron spectroscopy were used to evaluate the morphology, the structure, the surface composition, and the electronic structure of the catalysts. Their electrochemical properties were studied towards CO stripping measurements in acidic solution; a reaction of critical issue to liquid fuel cells. It was discovered that rhodium (Rh) film deposited under 5 Torr of He background pressure showed the highest electroactive surface area, and the lowest onset potential of CO oxidation demonstrating an enhancement of the CO poisoning resistance. The reason for such enhanced electrocatalytic activity is ascribed to the high porosity and roughness of the Rh surface. Compared to Pt films made under similar processing conditions (5 Torr of He), Rh film displayed higher roughness factor of 58.5 (vs. 30 for Pt), a net charge due to oxidation and desorption of the CO adlayer of 385 μC cm −2 (vs. 350 μC cm −2 for Pt), and an onset potential for CO oxidation of 30 mV less anodic than that at Pt electrode.
Nanostructured Pt thin film catalysts of various morphologies have been synthesized by pulsed laser deposition and studied towards enhancing their tolerance to CO poisoning, a reaction of critical issue to liquid fuel cells. It was discovered that Pt film deposited under 5 Torr of He background pressure showed the highest electroactive surface area and the lowest onset potential of CO oxidation demonstrating an enhancement of the CO poisoning resistance. The reason for such enhanced electrocatalytic activity is ascribed to the high roughness of Pt surface. This study further provides a methodology for the proper design of electrocatalysts that might be considered to be developed by the pulsed laser deposition technique.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.