Metal-Nitrogen-Carbon Catalysts for Oxygen Reduction in PEM Fuel Cells: Self-Template Synthesis Approach to Enhancing Catalytic Activity and Stability

Yanghua He; Qiang Tan; Leilei Lu; Joshua Sokolowski; Gang Wu

doi:10.1007/s41918-019-00031-9

Electrochemical Energy Reviews ›› 2019, Vol. 2 ›› Issue (2) : 231 -251. DOI: 10.1007/s41918-019-00031-9

Review Article

Metal-Nitrogen-Carbon Catalysts for Oxygen Reduction in PEM Fuel Cells: Self-Template Synthesis Approach to Enhancing Catalytic Activity and Stability

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¹ Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, 14260, Buffalo, state, US

^e gangwu@buffalo.edu

Yanghua He is currently a Ph.D. student in Department of Chemical and Biological Engineering at the University at Buffalo (UB), SUNY. She received her bachelor degree in Chemistry at Sun Yat-Sen University in 2015, followed by research training at Dalian Institute of Chemical Physics, CAS (2015–2016). Her researches focus on functional materials for catalysts and energy storage with an emphasis on PGM-free catalysts for PEM fuel cell and metal–air battery applications.

Qiang Tan is currently a postdoc in Prof. Gang Wu’s group. He obtained his Ph.D. degree from Harbin Institute of Technology (2014). Then, he joined Prof. Gang Wu’s group as a visiting scholar at the University at Buffalo, the State University of New York. His current research interest is the design of nanoscale materials for electrocatalysis.

Leilei Lu is currently a visiting scholar in Prof. Gang Wu’s group at the University at Buffalo. She is a lecturer at College of Science, Department of Applied Chemistry, Xi’an University of Technology. She obtained her Ph.D. degree from Harbin Institute of Technology (2009). Her current research interest is electrocatalysis and nanomaterials for electrochemical energy storage and conversion.

Josh Sokolowski is currently a master student in Prof. Gang Wu’s Group at the University at Buffalo (UB). He received his bachelor degree from UB in 2018. His current research interest is electrocatalysis for PEM fuel cell application.

Gang Wu is an associate professor in the Department of Chemical and Biological Engineering at the University at Buffalo (SUNY-Buffalo). He completed his Ph.D. studies at the Harbin Institute of Technology in 2004, followed by extensive postdoctoral training at Tsinghua University (2004–2006), the University of South Carolina (2006–2008), and Los Alamos National Laboratory (LANL) (2008–2010). He was promoted as a staff scientist at LANL in 2010. Then, he joined SUNY-Buffalo as a tenure-track assistant professor in 2014 and was early promoted as a tenured professor in 2018. His research focuses on functional materials and catalysts for electrochemical energy technologies. To date, he has published 200 papers with citations of > 15,000 times with an H index of 60. Dr. Wu was acknowledged by Clarivate Analytics as one of 2018 Highly Cited Researchers.

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Abstract

Proton exchange membrane fuel cells (PEMFCs) are leading candidates in the utilization of clean energy resources for application in transportation, stationary, and portable devices. In PEMFCs, cathode catalysts are crucial for overall performance and durability due to kinetically slow oxygen reduction reactions (ORR). Because platinum (Pt), a state-of-the-art ORR catalyst, is rare and expensive, the development of high-performance platinum metal group (PGM)-free catalysts is highly desirable for future fuel cell technologies. Among the various PGM-free catalyst formulations, metal and nitrogen co-doped carbon (M-N-C, M: Fe, Co, or Mn) catalysts have exhibited encouraging activity and stability in acidic media for ORR and possess great potential to replace Pt in the future. Therefore, based on our extensive experience in the field of ORR catalysis, this review will comprehensively summarize the basic principles in the design and synthesis of M-N-C catalysts for durable, inexpensive, and high-performance PEMFCs with an emphasis on Co- and Mn-N-C catalysts to avoid Fenton reactions between Fe²⁺ and H₂O₂, which can generate free radicals and lead to the degradation of catalysts, ionomers, and membranes in PEMFCs. Furthermore, template-free 3D hydrocarbon frameworks as attractive precursors to advanced M-N-C catalysts will be discussed to significantly enhance intrinsic ORR activities in acidic media. In addition, long-term performance durability of M-N-C cathodes will be discussed extensively to provide potential solutions to enhance catalyst stability in PEMFCs. Finally, this review will provide an overall perspective on the progress, challenges, and solutions of PGM-free catalysts for future PEMFC technologies.

Keywords

Oxygen reduction / PGM-free catalysts / Electrocatalysis / Fuel cells / Energy conversion

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Yanghua He, Qiang Tan, Leilei Lu, Joshua Sokolowski, Gang Wu. Metal-Nitrogen-Carbon Catalysts for Oxygen Reduction in PEM Fuel Cells: Self-Template Synthesis Approach to Enhancing Catalytic Activity and Stability. Electrochemical Energy Reviews, 2019, 2(2): 231-251 DOI:10.1007/s41918-019-00031-9

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