Synthesis and electrochemical oxygen reduction reaction activities of palladium-based intermetallic nano-electrocatalysts

Abstract

Changing the atomic structure of a material to alter its characteristics is a key and powerful technique in materials research. Electrocatalytic applications are a growing field for structurally long range ordered materials. Similar electrocatalysts with a disordered structure, however, are unable to perform as well as those with an ordered structure because of the specific functionalities that may be achieved by the ordered structure. There has been a lot of interest in using highly active and stable ordered intermetallics as electrocatalysts for polymer electrolyte membrane fuel cells (PEMFCs). Electrocatalysts based on palladium have lately emerged as one of the most promising classes for the oxygen reduction reaction (ORR) in alkaline media because of their superior ORR activity and durability at lower prices than platinum. As electrocatalysts for fuel cells, palladium-based intermetallic nano-electrocatalysts (Pd-INECs) have gained a lot of interest in recent years. Pd-INECs have exceptional catalytic activity and great stability due to their well-defined composition and predictable control over structural, geometric, and electronic effects. In this short article, we will briefly go through the current state of knowledge on Pd-INECs for cathodic ORR in fuel cells. The first step is a brief review of the synthetic ways in which Pd-INECs with a predetermined stoichiometry and a well-defined atomic structure will be discussed. We also emphasized the use of Pd-INECs in electrochemical ORR operations as a second part of the review. Methods are comprehensively reviewed for enhancing the electrocatalytic activity of Pd-INECs. Finally, suggestions for future research directions and current difficulties are made.