Series Reports from Professor Wei’s Group of Chongqing University: Advancements in Electrochemical Energy Conversions (1/4): Report 1: High-Performance Oxygen Reduction Catalysts for Fuel Cells

Abstract

Two major challenges, high cost and short lifespan, have been hindering the commercialization process of low-temperature fuel cells. Professor Wei’s group has been focusing on decreasing cathode Pt loadings without losses of activity and durability, and their research advances in this area over the past three decades are briefly reviewed herein. Regarding the Pt-based catalysts and the low Pt usage, they have firstly tried to clarify the degradation mechanism of Pt/C catalysts, and then demonstrated that the activity and stability could be improved by three strategies: regulating the nanostructures of the active sites, enhancing the effects of support materials, and optimizing structures of the three-phase boundary. For Pt-free catalysts, especially carbon-based ones, several strategies that they proposed to enhance the activity of nitrogen-/heteroatom-doped carbon catalysts are firstly presented. Then, an in-depth understanding of the degradation mechanism for carbon-based catalysts is discussed, and followed by the corresponding stability enhancement strategies. Also, the carbon-based electrode at the micrometer-scale, faces the challenges such as low active-site density, thick catalytic layer, and the effect of hydrogen peroxide, which require rational structure design for the integral cathodic electrode. This review finally gives a brief conclusion and outlook about the low cost and long lifespan of cathodic oxygen reduction catalysts.

Keywords

Fuel cell / Oxygen reduction reaction / Pt-based catalyst / Carbon-based catalyst

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