Hydrogen Absorption in Palladium‐Based Nanocrystals for Electrocatalysis Investigation

Hydrogen absorption in transition metals has received enormous attention for applications such as the hydrogen storage, sensing and corrosion. In particular, the Pd‐H system is a simple and classical metal hydride system that serves as a platform for a deeper understanding of hydrogen behavior. In the past few years, Pd‐H has been reported as electrocatalyst in multiple reactions, whereas the impact of hydrogen absorption/desorption in electrocatalytic applications remains unclear. Therefore, in this concept, factors influencing the hydrogen adsorption/desorption of palladium in the gas phase, such as facet engineering, ligand effects, and alloying effects, are summarized. Subsequently, in the context of electrocatalysis, factors affecting electrochemical hydrogen adsorption/desorption are outlined. Particularly, prospects for the further investigation of electrochemical hydrogen adsorption/desorption in catalysis are discussed. This concept aims at emphasizing the importance of hydrogen absorption in Pd nanocrystals and summarize its applications, influencing factors, and prospects in the field of electrocatalysis. The absorption/desorption behaviour of hydrogen, as an effective method to modulate the surface structure of Pd nanocrystals, can be appropriately employed by the electrocatalysis and catalysis community as the strategies for material design or surface treatment.