Graphynes as Promising Cathode Material of Fuel Cell: Improvement of Oxygen Reduction Efficiency

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• 作者：Baotao Kang ; Jin Yong Lee
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：June 5, 2014
• 年：2014
• 卷：118
• 期：22
• 页码：12035-12040
• 全文大小：332K
• 年卷期：v.118,no.22(June 5, 2014)
• ISSN：1932-7455

文摘

The sluggish kinetics of oxygen reduction reaction (ORR) on cathode is an invariable bottleneck in the fuel cell industry. Recently, a rising 2D carbon allotrope, graphyne with fascinating properties, appears to be a potential candidate to promote fuel cell performance. We investigated ORR process on three different graphyne models by density functional theory calculations. Because of the acetylenic linkage (鈭扖鈮鈭? insertion, some carbon atoms in graphyne are positively charged to facilitate O₂ dissociation. It was found that the first two-hydrogen addition produces a water molecule, and then the next two hydrogens furnish another water formation accompanied by the recovery of graphyne planarity. The ORR process on three graphyne models exhibits an efficient four-electron process. Moreover, the 18-membered rings in 伪- and 尾-graphyne allow O₂ penetration nearly barrierlessly, hence improving ORR efficiency. Our results imply that 伪- and 尾-graphyne systems are promising cathode materials to promote the performance of fuel cells.