Hetero-shaped coral-like catalysts through metal-support interaction between nitrogen-doped graphene quantum dots and PtPd alloy for oxygen reduction reaction

The development of efficient and durable electrocatalysts is essential for the practical application of fuel cells. Metal-support interaction (MSI) is an important concept in heterogeneous catalysis, which can construct the structure of catalyst and improve the reaction activity and stability of catalyst. Based on this, a simple and efficient method is innovatively proposed to synthesize coral-like special structure catalyst by utilizing the crush capacity of high energy gamma-rays and the structure-induced effect of MSI between PtPd alloy and nitrogen-doped graphene quantum dots. The electrocatalyst demonstrates superior long-term durability due to the structure of catalyst is not easy to collapse under suitable MSI. Meanwhile, the unique coral-like structure provides a larger contact area, abundant mass transfer channels, and full exposure of active sites, which are advantageous to improve electrocatalytic activity. The oxygen reduction reaction performance of optimal catalyst (NGQDs140-PtPd) was far superior to that of the commercial 20% Pt/C in alkaline medium, including onset potential (959 mV), half-wave potential (860 mV) and stability (the residual current density was 86.5% after long-term stability test). Therefore, coral-like shaped catalysts are expected to become a member of high-efficiency oxygen reduction catalysts in practical applications. (C) 2020 Elsevier Ltd. All rights reserved.