Defect structure analysis of heterointerface between Pt and CeOx promoter on Pt electro-catalyst

Pt–CeOx/C (1.5 ≤ x ≤ 2) electro-catalyst is one of the most promising cathode materials for use in polymer membrane electrolyte fuel cells. To clarify the microstructure of Pt–CeOx heterointerface, we prepared Pt-loaded CeOx thin film on conductive SrTiO3 single crystal substrate by using a stepwise process of pulse laser deposition method for the preparation of epitaxial growth CeOx film followed by an impregnation method which loaded the Pt particles on the CeOx film. The electrochemistry observed for the Pt-loaded CeOx thin film on the conductive single crystal substrate was examined by using cyclic voltammetry in 0.5 M H2SO4 aqueous solution, and a cross-sectional image of the aforementioned Pt–CeOx thin film electrode was observed using a transmission electron microscope. The electrochemistry observed for Pt–CeOx thin film electrode clearly showed the promotion effect of CeOx. Also, the microanalysis indicated that unique, large clusters that consisted of C-type rare-earth-like structures were formed...