Hydrogen Oxidation-Selective Electrocatalysis by Fine Tuning of Pt Ensemble Sites to Enhance the Durability of Automotive Fuel Cells
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- 作者：Su-Won Yun ; Dr. Shin-Ae Park ; Dr. Tae-June Kim ; Dr. Jun-Hyuk Kim ; Gi-Woong Pak and Prof. Yong-Tae Kim
- 刊名：ChemSusChem
- 出版年：2017
- 出版时间：February 8, 2017
- 年：2017
- 卷：10
- 期：3
- 页码：489-493
- 全文大小：979K
- ISSN：1864-564X
文摘
A simple, inexpensive approach is proposed for enhancing the durability of automotive proton exchange membrane fuel cells by selective promotion of the hydrogen oxidation reaction (HOR) and suppression of the oxygen reduction reaction (ORR) at the anode in startup/shutdown events. Dodecanethiol forms a self-assembled monolayer (SAM) on the surface of Pt particles, thus decreasing the number of Pt ensemble sites. Interestingly, by controlling the dodecanethiol concentration during SAM formation, the number of ensemble sites can be precisely optimized such that it is sufficient for the HOR but insufficient for the ORR. Thus, a Pt surface with an SAM of dodecanethiol clearly effects HOR-selective electrocatalysis. Clear HOR selectivity is demonstrated in unit cell tests with the actual membrane electrode assembly, as well as in an electrochemical three-electrode setup with a thin-film rotating disk electrode configuration.