A protective roasting strategy for preparation of stable mesoporous hollow CeO2 microspheres with enhanced catalytic activity for one-pot synthesis of imines from benzyl alcohols and anilines

Abstract

A novel protective roasting strategy was applied to prepare mesoporous hollow CeO₂ microspheres (mh-CeO₂) using silica as both a hard template and a roasting protectant. Through detailed characterization techniques such as SEM, TEM, EDX, FT-IR, XRD, XPS, and N₂ adsorption–desorption, it could be determined that hollow CeO₂ microspheres with good dispersibility and crystallinity, uniform spherical morphology and suitable pore width as heterogeneous catalysts had been successfully prepared. mh-CeO₂ showed much higher catalytic activity than the as-prepared SiO₂@CeO₂ and reported CeO₂ catalysts for one-pot synthesis of imines from anilines and benzyl alcohols, which is attributed to its super-high specific surface area and mesoporous hollow structure. In addition, this protective roasting strategy can also superiorly stabilize the hollow structure during the reaction, recovery and multiple calcination processes.