Construction of Pd-based nanocatalysts for fuel cells: opportunities and challenges

Nanostructured Pd-based electrocatalysts have a large impact on cost, performance, and durability in the development of fuel cells. This review article provides an overview of recent advances in Pd-based electrocatalysts with a well-defined structure that can be applied for alcohol oxidation and oxygen reduction in an alkaline medium in direct alcohol fuel cells. These Pd-based catalytic materials include Pd electrocatalysts with different morphologies, monodisperse bimetallic Pd-based nanoparticles with different compositions and Pd-based nanoparticles with a well-controlled shape. Emphasis is placed on the atomic-level design of the nanoparticles' structure, and the origin of their electrochemical activity. The ways to enhance the electrocatalytic performance and design principles for Pd-based catalysts are discussed. This will help to shed light on the future development of non-Pt catalysts for fuel cells and accelerate the commercialization of fuel cell technology.