Nanoporous CeO₂–ZrO₂ Oxides for Oxidation of Volatile Organic Compounds

Abstract

Here, mixed nanostructured ceria/zirconia oxides have been prepared either by wet impregnation on a nanostructured ZrO2 or by co-condensation through an EISA-derived pathway. This latter method and the impregnation on amorphous ZrO2 followed or not by a heating at 480°C lead to a uniform cerium distribution in the zirconia framework and solid solutions are formed. Stabilization of the tetragonal structure of nano ZrO2 with the increase of the cerium content is observed by XRD and Raman spectroscopy. The surface Ce/Zr molar ratio determined by XPS is very closed to the bulk one, calculated from the X-ray fluorescence analysis. On the opposite, the appearance of nano sized ceria particles with the increase of the cerium content, a monoclinic/tetragonal mixture and an enrichment of the surface in cerium are noted if the impregnation is carried out on a nanostructured ZrO2 previously calcined at 480°C. The obtained catalysts have been tested for the oxidation of toluene, used as a model volatile organic compound. The catalytic efficiency of the mixed oxides has also been compared to the one of a pure commercial ceria. Results show that the preparation method has a significant effect on the catalytic properties of the materials. Although pure ceria presents the best activity and selectivity, the nanostructured ZrO2 previously calcined at 480°C and impregnated by 10 mol% of CeO2 is almost as efficient as pure ceria.

Nanoporous oxide electrodes for energy conversion and storage devices

“…, sodium dodecyl sulfate, sodium dodecylbenzene sulphonate, etc. ), and non-ionic surfactant (block co-polymer like PS- b -PEO, 161 Pluronic PE10300, 162 P-123, 163–165 polyvinylpyrrolidone (PVP), 166 etc. ).…”

Carbon Monoxide and Propylene Catalytic Oxidation Activity of Noble Metals (M = Pt, Pd, Ag, and Au) Loaded on the Surface of Ce0.875Zr0.125O2 (110)

“…The state of Ce can easily shuttle between Ce 3+ and Ce 4+ , which gives CeO 2 excellent oxygen-storage capacity (OSC) and a large number of surface oxygen vacancies [7,8]. To improve the thermal stability and low-temperature redox performance of CeO 2 , it is often doped with zirconium dioxide (ZrO 2 ) to form a Ce-Zr mixed oxide, namely a Ce x Zr 1−x O 2 solid solution [9][10][11]. Compared with pure CeO 2 catalysts, the thermal stability and oxygen-storage performance of Ce x Zr 1−x O 2 solid solutions have been greatly improved.…”

Co3O4 Nanoparticle-Decorated SiO2 Nanotube Catalysts for Propane Oxidation

“…In recent years, the economy has grown rapidly with the development of contemporary society, and related environmental problems have attracted increasing attention. − Volatile organic compound (VOC) emissions from automobile exhaust and industrial processes not only cause serious environmental pollution but also threaten human health. − Over the past few decades, catalytic oxidation has become the most effective and widely used technology to eliminate various VOC pollutants. − Noble metal-based catalysts exhibit outstanding VOC conversion ability due to their strong oxidation properties. , However, some disadvantages, such as high price, ease of poisoning, and sintering restrict their large-scale application. , Therefore, it is essential to develop highly efficient noble metal-free catalysts.…”