Synthesis and Electrocatalytic Applications of Polyelemental Nanoparticles

Polyelemental nanoparticles (NPs) are an emerging class of nanomaterials that have been widely used in many fields including energy and catalysis. Establishing reliable synthetic methods that encompass a wide range of elements while allowing precise control of other particle parameters is crucial for the development of polyelemental NPs. In the past decade, synthesis methods for heterojunction, core–shell, solid solution, intermetallic, and amorphous polyelemental NPs have been extensively reported. Here, we summarize top-down and bottom-up synthetic strategies that overcome the challenges in balancing the different reduction potentials, atomic sizes, lattice structures, and miscibility of various elements to achieve delicate control of particle structure, size, and composition. As a unique characteristic of polyelemental NPs, the vast design space of catalytic sites can be used to systematically tune the adsorption of reaction species, which allows the creation of nanocatalysts with exceptional performance. In particular, we present some studies utilizing polyelemental NP catalysts for energy-related reactions, such as water splitting, fuel cell reactions, and carbon dioxide reduction reaction. The NP catalysts are categorized and discussed based on their elemental distribution differences, namely, disordered solid solutions, ordered intermetallics, and multiphase NPs. The mechanisms of catalytic enhancement on different types of polyelemental NPs are compared, providing insights into the design of efficient polyelemental nanocatalysts for the energy field.