Recent progress of mesoscience in design of electrocatalytic materials for hydrogen energy conversion

Electrocatalytic materials with different morphologies,sizes,and components show different catalytic behavior in various heterogeneous catalytic reactions.It has been proved that the catalytic properties of these materials are strongly influenced by several factors at different levels,including the electrode morphology,reaction channels,three-phase interface,and surface active sites.Recent developments of mesoscience allow one to study the relationship between the apparent catalytic performance of electro-catalytic materials with these factors from different levels.In this review,following a brief introduction of new mesoscience,we summarize the effect of mesoscience on electrocatalytic material design,including modulating the geometric and electronic structures of materials focusing on morphology(particulate,fiber,film,array,monolith,and superlattice),pore structure(microporous,mesoporous,and hierarchical),size(single atoms,nanoclusters,and nanoparticles),multiple components(alloys,heterostructures,and multiple ligands),and crystal structures(crystalline,amorphous,and multiple crystal phases).By evaluating the electrocatalytic performance of catalytic materials tuned at the mesoscale,we paint a picture of how these factors at different levels affect the final system performance and then provide a new direction to better understand and design catalytic materials from the viewpoint of mesoscience.