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In this study, atomic layer deposition (ALD) was used to deposit Pt thin films as an electrode/catalyst layer for solid oxide fuel cells. I−V measurements were performed to determine the dependence of the fuel cell performance on the Pt film thickness at different operating temperatures. The measured fuel cell performance revealed that comparable peak power densities were achieved for ALD-deposited Pt anodes with only one-fifth of the platinum loading relative to dc-sputtered Pt anodes. The Pt films fabricated by dc sputtering and ALD had different microstructure, which accounted for the difference in their performance as a fuel cell anode. In addition to the continuous electrocatalyst layer, a micropatterned Pt structure was fabricated via area-selective ALD and used as a current collector grid/patterned catalyst for the fuel cells. An improvement of the fuel cell performance by a factor of 10 was observed using the Pt current collector grid/patterned catalyst integrated onto cathodic La0.6Sr0.4Co0.2Fe0.8O3-δ. The study suggests the potential to achieve improved performance and/or lower loadings using ALD for catalysts in fuel cells.

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In this study, we demonstrate a novel approach;atomic layer deposition (ALD);for the synthesis and investigation of Pt-Ru catalyst structures toward the oxidation of stoichiometric (1:1) methanol solutions in advanced direct methanol fuel cells. Two types of thin-film materials are investigated as catalysts for methanol oxidation: Pt-Ru films of varying ruthenium content that are co-deposited by ALD, and Pt skin catalysts made by depositing porous platinum layers of different thickness by ALD on sputtered ruthenium films. MeCpPtMe 3 and Ru(Cp) 2 are used as precursors for Pt and Ru ALD, respectively, together with pure O 2 as the counter reactant. The electrochemical behavior of the co-deposited Pt-Ru catalysts and the Pt skin catalysts for methanol oxidation is characterized using chronoamperometry and cyclic voltammetry in a 0.5 M H 2 SO 4 /16.6 M CH 3 OH electrolyte at room temperature. The results illustrate that the optimal stoichiometric Pt:Ru ratio for the co-deposited catalysts is ∼1:1, which is consistent with our previous study on sputtered Pt-Ru catalysts using the same CH 3 OH concentration. Moreover, we report that the catalytic activity of sputtered ruthenium catalysts toward methanol oxidation is strongly enhanced by the ALD Pt overlayer, with such skin catalysts displaying superior catalytic activity over pure platinum. The mechanistic aspects of our observations are discussed.