Time‐Dependent Surface Oxidation of Pd Nanocubes and its Role in Controlling Catalytic Performance

Abstract

AbstractThe surface evolution of catalysts, which leads to the changes in physicochemical properties for various catalysts under different storage temperatures and amounts of time, is an important issue for altering catalytic performance. However, the influence of such a surface evolution under different storage conditions on the catalytic performance is often neglected, albeit enormous studies have been carried out in past decades. In this work, Pd nanocrystals are prepared through facile aqueous synthetic methods and employed as model catalysts for catalytic reactions. Our investigation reveals that the storage duration of Pd nanocubes has great influence on their catalytic performance. Generally, the catalytic performance of Pd nanocubes show a dramatically enhanced catalytic performance for Heck coupling reaction after a storage duration of 25 days. According to XPS characterization, this enhancement in catalytic performance is attributed to the presence of oxidized Pd on the surface of Pd nanocubes. Moreover, it is further discovered that the change in storage temperature and storage environment can also contribute to the surface state evolution of Pd nanocubes, affecting their catalytic performance. This work shows not only the storage condition‐dependent catalytic performance of the Pd nanocubes, but also the evidence that allows us to understand the structure sensitivity of Pd nanocubes over different storage condition.