Templated Synthesis of Crystalline Mesoporous CeO2 with Organosilane-Containing Polymers: Balancing Porosity, Crystallinity and Catalytic Activity

Abstract

We report the synthesis of ordered mesoporous ceria (mCeO2) with highly crystallinity and thermal stability using hybrid polymer templates consisting of organosilanes. Those organosilane-containing polymers can convert into silica-like nanostructures that further serve as thermally stable and mechanically strong templates to prevent the collapse of mesoporous frameworks during thermal-induced crystallization. Using a simple evaporation-induced self-assembly process, control of the interaction between templates and metal precursors allows the co-self-assembly of polymer micelles and Ce3+ ions to form uniform porous structures. The porosity is well-retained after calcination up to 900 oC. After the thermal engineering at 700 oC for 12 h (mCeO2-700-12 h), mCeO2 still has a specific surface area of 96 m2/g with a pore size of 14 nm. mCeO2 is demonstrated to be active for electrochemical oxidation of sulfite. mCeO2-700-12 h with a perfect balance of crystallinity and porosity shows the fastest intrinsic activity that is about 84 times more active than bulk CeO2 and 5 times more active than mCeO2 that has a lower crystallinity.