Transition metal nanoparticles as electrocatalysts for ORR, OER, and HER

Electrochemical reactions of the oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and oxygen evolution reaction (OER) play an essential role in energy conversion and storage technologies to meet the future demands for clean, renewable, and sustainable energy. However, the sluggish kinetics of these reactions has limited their practical efficiency; thus, the development of high-active electrocatalysts is of significance to improve the performance of these reactions. Various transition metal catalysts have been developed, and have demonstrated impressive potential to accelerate catalytic activity and stability toward ORR, HER, and OER. This chapter discusses recently developed transition metal nanoparticle-based catalysts for the ORR, HER, and OER in terms of effective synthesis approaches, such as hydrothermal, solvothermal, chemical reduction, and electrochemical deposition technologies. Their structural and physicochemical properties, as well as applications for the ORR, HER, and OER, are also discussed.