The cover picture shows facile photochemical synthesis, direct in situ TEM characterization, and effective catalytical applications of sponge‐like porous Pd nano particles. In situ liquid cell TEM observation not only confirms the actual existence of the sponge‐like Pd in a liquid solution, but also shows such Pd nanostructure is in a dynamic stable state, which is beneficial for the material exchange and the catalytic performance improvement. The expected catalytic activity improvement is supported by such as the 4‐nitrophenol reduction reactions, which is important both for the environment and the industry. More details are discussed in the article by Chen et al. on page 565–569.
