Recent progress in low-dimensional palladium-based nanostructures for electrocatalysis and beyond

Low-dimensional palladium (Pd)-based nanomaterials have been widely used as electrocatalysts, especially in the field of fuel cells, due to their inherent advantages, such as high electron mobility, abundant active sites, high aspect ratio, and unique electronic properties. A thorough understanding of structure–activity relationships of low-dimensional Pd-based nanostructures plays a critical role in the pursuit of high-efficiency electrocatalysts. In this review, we first summarize the state-of-the-art research on the synthesis and rational design of low-dimensional Pd-based nanostructures, including one-dimensional nanowires and two-dimensional nanosheets. Next, by correlating the properties of materials with the structure, relevant strategies toward advanced Pd-based electrocatalysts including alloying, surface engineering, defect engineering, interface engineering and strain engineering are classified. We also discuss the promotion role of various strategies in different applications, including electrocatalytic oxygen reduction reaction (ORR), formic acid oxidation reaction (FAOR), methanol oxidation reaction (MOR), ethanol oxidation reaction (EOR), hydrogen evolution reaction (HER) and CO2 reduction reaction (CO2RR), as well as some heterogeneous reactions. Finally, the current challenges and future prospects regarding the development of Pd-based nanomaterials are proposed.