This review summarises recent advances in the synthesis and electrocatalytic application of intermetallic nanostructures.

Intermetallic structures whose regular atomic arrays of constituent elements present unique catalytic properties have attracted considerable attention as efficient electrocatalysts for energy conversion reactions. Further performance enhancement in intermetallic catalysts hinges on constructing catalytic surfaces possessing high activity, durability, and selectivity. In this Perspective, we introduce recent endeavors to boost the performance of intermetallic catalysts by generating nanoarchitectures, which have well-defined size, shape, and dimension. We discuss the beneficial effects of nanoarchitectures compared with simple nanoparticles in catalysis. We highlight that the nanoarchitectures have high intrinsic activity owing to their inherent structural factors, including controlled facets, surface defects, strained surfaces, nanoscale confinement effects, and a high density of active sites. We next present notable examples of intermetallic nanoarchitectures, namely, facet-controlled intermetallic nanocrystals and multidimensional nanomaterials. Finally, we suggest the future research directions of intermetallic nanoarchitectures.

Hollow skeletal nanomaterials, such as nanoframes and nanocages, represent a class of advanced electrocatalysts and exhibit excellent performance in various electrochemical energy conversion reactions. Their three-dimensional (3D) framework, which allows a high surface-area-to-volume ratio, efficient molecular accessibility, and nanoscale confinement effect, leads to higher catalytic activity compared to solid nanoparticle (NP)-based catalysts without requiring the use of a significant amount of precious metal. In this Perspective, we present notable exemplars of skeletal nanostructures that have demonstrated superior activity over solid NP-based catalysts. In particular, we highlight that the 3D framework in skeletal nanostructures consists of inherently reactive catalytic surfaces and discuss a multitude of factors affecting the excellent performance of skeletal nanocatalysts. We next introduce the design strategies that promote the catalytic activity and durability of skeletal nanostructures, including the strengthening of framework structures and the reorganization of the atomic array in a skeletal nanostructure. Finally, we provide future research directions in this emerging class of catalysts.

Distinctive surface functional groups on 3D MXenes as Pt-supports are correlated with optimized Pt–H affinity and HER activity in alkaline media.