A facile synthesis for cauliflower like CeO₂ catalysts from Ce-BTC precursor and their catalytic performance for CO oxidation

Highlights: • CeO₂ was obtained from direct decomposition of Ce-based metal organic framework. • Varied morphology was obtained depending on the calcination temperature. • Catalytic performance towards CO oxidation was investigated. • Cauliflower CeO₂ obtained at calcined temperature of 500 °C displays high activity. - Abstract: The paper presents a novel and facile method for preparing cauliflowerlike CeO₂ through direct decomposition of cerium based metal-organic framework (MOF) Ce-BTC (BTC = 1,3,5-benzenetricarboxylic acid) straw in air. Several analytical tools such as Scanning electron microscopy (SEM), X-ray diffraction (XRD), Thermogravimetric (TG), N₂ adsorption-desorption, Temperature programmed reduction (TPR), Raman, X-ray photoelectron spectroscopic (XPS) and Photoluminescence (PL) have been used to characterize Ce-BTC and CeO₂. The Ce-BTC calcined at 500 °C (CeO₂-500) maintains the morphology of its template "Ce-BTC" and forms a special cauliflower-like structure. XRD patterns showed that the catalyst has a perfect CeO₂ crystal structure and has a smaller particle size. The prepared CeO₂ cauliflowers exhibit excellent catalytic activities, long-term stability, and cycling stability for CO oxidation. The improved catalytic activities could be attributed to porous nanorods of CeO₂ cauliflowers, which provide more active sites and oxygen vacancy for CO oxidation.