Phosphorus-Doped Carbon as Efficient Electrocatalysts for Oxygen Reduction Reaction

Abstract

Electrocatalytic oxygen reduction reaction (ORR) has attracted much attention due to its importance in fuel cells and metal–air batteries [1-3]. The ORR in fuel cells and metal-air batteries require catalysts to accelerate the reaction rate owing to its sluggish kinetics and complicated reaction mechanism. Pt-based ca talysts are known to be the most active catalysts. However, Pt is scarce and expensive. The development of low-cost and efficient catalysts for the ORR is highly desirable [4,5]. Heteroatoms-doped carbon meterials have been explored as alternative electrocatalysts for the ORR due to their more abundance, lower price and high activity [6,7]. In this work, phosphorus (P)-doped carbon is facilely synthesized by both ex-situ and in-situ doping method. The catalytic activity of P-doped carbon for the ORR in 0.1 M KOH solution has been studied by using a rotating ring-disk electrode (RRDE) technique. The RRDE results show that P-doped carbon exhibits excellent catalytic activity for the ORR (Fig.1 and Fig.2)and long-term stability in basic media (Fig.3 ). The high elecctrocatalytic activity and durability of P-doped carbon are primarily attributed to the P-doping in the carbon lattice. Moreover, the factors that influence the ORR activity of P-doped microporous carbon are studied in detail. This kind of low cost, highly active and sustainable P-doped carbon xerogels could be used as a potential electrocatalyst for the cathodic ORR in fuel cells and metal-air batteries.Acknowledgements This work is supported by National Natural Science Foundation of China (Nos. 51272167 and 21206101 ), Natural Science Foundation of the Higher Education Institutions of Jiangsu Province, China (12KJB430010) and Sino-German Network on Electromobility.