X-Ray Absorption Study of Sputtered Pt-CeO2 Catalyst Used in PEM-FC

Abstract

The proton exchange membrane fuel cell (PEMFC) is supposed to be an environmentally friendly near-future power source for mobile devices. The crucial problem in the fuel cell technology field is the finding of a stable, efficient and economical catalyst for hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) at working conditions of PEMFC. The Pt catalyst, which is widely used due to fact that this catalyst is only really functional enough, is an expensive material. Moreover, unfortunately all of the less expensive Platinum bimetallic alloys as ORR catalysts enhancing the activity rapidly degrade in acidic environment and ORR condition [1]. We have already shown that Pt-CeO2sputtered catalyst exhibits high specific power (thousand-times higher power per mg of platinum and only few times lower power density in comparison with Pt reference catalyst) so such material could be an appropriate for PEMFC anode (HOR) [2,3,4]. Presented work is aimed for understanding the role of Pt and Ce chemical states and Pt-Ce interactions in HOR and ORR catalytic activity investigated in-situ using X-ray Absorption Near Edge Structure (XANES). Additionally, the performance and endurance of this catalyst obtained through direct testing in fuel cell test station are presented. Then, morphology determined by scanning electron microscopy and photoelectron spectroscopy results is shown. [1] G.-F. Wei et al., Energy Environ. Sci.,4(2011) 1268 [2] R. Fiala et al., J. Nanosci. Nanotechnol.,11 (2011) 5062–5067 [3] V. Matolin et al., Langmuir, 26 (2010) 12824–12831 [4] V. Matolin et al., Int. J. Nanotechnol., 9 (2012) 680–694 Figure 1