Heteroatom-Doped Graphitic Carbon Catalysts for Efficient Electrocatalysis of Oxygen Reduction Reaction
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- 作者：Jintao Zhang ; Liming Dai
- 刊名：ACS Catalysis
- 出版年：2015
- 出版时间：December 4, 2015
- 年：2015
- 卷：5
- 期：12
- 页码：7244-7253
- 全文大小：691K
- ISSN：2155-5435
文摘
The oxygen reduction reaction (ORR) plays an important role in renewable energy technologies, such as fuel cells and metal鈥揳ir batteries. Along with the extensive research and development of nonprecious metal catalysts (NPMCs) to reduce/replace Pt for electrocatalytic reduction of oxygen, a new class of heteroatom-doped metal-free carbon catalysts has been recently developed, which, as alternative ORR catalysts, could dramatically reduce the cost and increase the efficiency of fuel cells and metal鈥揳ir batteries. The improved catalytic performance of heteroatom-doped carbon ORR catalysts has been attributed to the doping-induced charge redistribution around the heteroatom dopants, which lowered the ORR potential and changed the O2 chemisorption mode to effectively weaken the O鈥揙 bonding, facilitating ORR at the heteroatom-doped carbon electrodes. Subsequently, this new metal-free ORR mechanism was confirmed by numerous studies, and the same principle has been applied to the development of various other efficient catalysts for not only ORR in fuel cells but also oxygen evolution reaction (OER) in metal鈥揳ir batteries and hydrogen evolution reaction (HER) in water-splitting systems. However, there are still some concerns about possible contributions of metal impurities to the ORR activities of these carbon catalysts. To avoid unnecessary confusion, therefore, it is important to clarify the situation. In this Perspective, we provide important aspects of the metal-free ORR catalysts with a critical analysis of the literature, along with perspectives and challenges of this rapidly growing field of practical significance.