Biomass‐derived nonprecious metal catalysts for oxygen reduction reaction: The demand‐oriented engineering of active sites and structures

Abstract : Oxygen reduction reaction (ORR) is an important electrochemical process for renewable energy conversion and storage applications such as fuel cells and metal‐air batteries. ORR is sluggish in kinetics and requires a large amount of platinum group metal (PGM)‐based catalysts to facilitate its slow reaction rate. Application of precious metals raises the cost and decreases the competitivity of these devices in the market. To address this challenge, PGM‐free ORR catalysts have been intensively investigated as an alternative to replace the PGM‐based catalysts and to promote the deployment of ORR‐related applications. In particular, the biomass holds promising potential to be used as the precursor material for PGM‐free ORR catalysts. This pathway has gained more and more attention in recent years. In this review, recent advances regarding biomass‐derived ORR catalysts are summarized with a focus on the rational design of both active sites and porous structures which are the two key factors in determining ORR performance of catalysts. At the end, the perspectives of development of biomass‐derived catalysts is discussed.