Preparation of high surface area catalyst for fuel cells by selective dealloying of Pt-based bimetallic alloy

Polymer membrane fuel cells are among the most promising alternative sources of clean energy. However, their commercialization is partially limited by the high price of platinum, which remains the only catalyst meeting the catalysis and durability requirements in such fuel cells. One of the promising strategies to overcome this obstacle is to increase as much as possible the active surface of the catalyst which can be realized by the preparation of high surface-to-volume Pt catalyst. This, in particular, can be realized by electrochemical dealloying of a pre-deposited Pt-based bimetallic alloy that can produce homogeneous 3D structured Pt coatings with open porosity.
This work will be focused on the preparation of such dealloyed high surface area Pt catalyst and their testing in a real fuel cell device. A Pt-based bimetallic alloy will be deposited by the magnetron sputtering method with regard to optimization of deposition parameters, composition and thickness of the catalytic layers. The alloy will be subsequently immersed into an etching solution while applying an electrical potential, which will cause selective dissolution of the less noble element. The more noble platinum will be thus left behind and will form high surface area structures. The morphology and composition of deposited layers will be characterized before and after electrochemical dealloying using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), respectively. The activity measurements will be done in commercial fuel cell test station.
The aim of the work is to study the connections between morphology and activity of catalytic layers.

Literature:

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[3] Oezaslan, M. et al. Size-Dependent Morphology of Dealloyed Bimetallic Catalysts: Linking the Nano to the Macro Scale. J. Am. Chem. Soc. 2012, 134, 514–524