Support Effects in Single-Atom Platinum Catalysts for Electrochemical Oxygen Reduction

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• 作者：Sungeun Yang ; Young Joo Tak ; Jiwhan Kim ; Aloysius Soon ; Hyunjoo Lee
• 刊名：ACS Catalysis
• 出版年：2017
• 出版时间：February 3, 2017
• 年：2017
• 卷：7
• 期：2
• 页码：1301-1307
• 全文大小：446K
• ISSN：2155-5435

文摘

Single-atom catalysts (SACs) provide an ideal platform for reducing noble-metal usage. SACs also exhibit unusual catalytic properties due to the absence of a metal surface. The role of the support may have a significant effect on the catalytic properties, similar to that of the ligand molecules in homogeneous catalysts. Here, the support effect was demonstrated by preparing a single-atom platinum catalyst on two different supports: titanium carbide (Pt1/TiC) and titanium nitride (Pt1/TiN). The formation of single-atom Pt was confirmed by STEM, EXAFS, and in situ IR spectroscopy. Pt1/TiC showed higher activity, selectivity, and stability for electrochemical H₂O₂ production than Pt1/TiN. Density functional theory calculations presented that oxygen species have strong affinity into Pt1/TiN, possibly acting as surface poisoning species, and Pt1/TiC preserves oxygen–oxygen bonds more with higher selectivity toward H₂O₂ production. This work clearly shows that the support in SACs actively participates in the surface reaction and does not just act as anchoring sites for single atoms.