Cerium–yttrium binary oxide microflower: synthesis, characterization and catalytic dehydration property

Abstract Cerium dioxide has a comparatively lower Ce 4+ /Ce 3+ redox pair, which leaves abundant oxygen vacancies on oxide lattice, also making incorporation of foreign ion and subsequent applications feasible and convenient. In this work, a series of cerium–yttrium mixed oxides were prepared by using polyvinylpyrrolidone as major template through sol–gel, which were further employed as catalyst for dehydration of aniline with formic acid into N-phenylformamide. Characterizations reveal that synthetic samples have a variety of morphologies including nanoparticle, microflower, and uniform microrods. The monitoring of particle size, zeta potential, and ultraviolet-visible (UV–Vis) of preparative solution indicate that self-assembly of polyvinylpyrrolidone and its subsequent reaction with metal ion determines sample morphology. In catalytic dehydration, all samples show high dehydration efficiencies that are comparable to those from anhydrous Na 2 SO 4 and combination of dicyclohexylcarbodiimide with 4-dimethylaminopyridine and dichloromethane shows better outputs than water. In association with structural analysis, cerium looks more active than yttrium, while yttrium mainly plays as a structure-directing and pore-forming agent. This study may contribute to micro-/nanofabrication of rare earth composites and their catalytic applications. Graphic abstract