The procedures leading to the preservation of catalytic performances of Au/ZrO2 samples have been investigated. The three potential causes of deactivation, namely the particle growth by sintering of gold nanoparticles, the metal leaching and the formation of un-reactive species which inhibit the reaction, have been evaluated. In particular, this paper deals with the stability of gold nanopartic...

Background Polymethyl methacrylate (PMMA) is widely used for the fabrication of removable prostheses. Recently, zirconium oxide nanoparticles (nano-ZrO2) have been added to improve some properties of PMMA, but their effect on the optical properties and tensile strength are neglected. Objective The aim of this study was to investigate the effect of nano-ZrO2 addition on the translucency and te...

The effect of pretreatment conditions on the oxidation state and activity of micelle-synthesized Pt nanoparticles supported on ZrO2 was studied for methanol decomposition and oxidation reactions. An O2-pretreatment is observed to be effective for producing clean, stable, and active nanoparticles. Pt-oxide species formed during such pretreatments were found to have little influence in methanol d...

We study the impact of (MnO2–ZrO2) nanoparticles on optical properties (PVA) polymer. Several samples were produced with different weight ratios nanoparticles. To prepare selected samples, casting method is used. record absorption spectrum, wavelengths 200–1100 nm are applied. have determined coefficient, energy gap for indirect transitions (forbidden and allowed), constants (such as dielectric...

In recent years, functionalized metal oxides have been gaining popularity for biomass conversion to fuels and chemicals due the global energy crisis. This study reports a novel catalyst based on noble immobilization zirconia that has successfully used in production of biofuel alkyl levulinates (ALs) from lignocellulosic biomass-derived levulinic acid (LA) under vapor-phase. The wet impregnation...

The pyrolysis of transition metal carboxylates into organically modified silica glass-ZrO2 hybrid sol-gel films yields composite materials containing cobalt oxide nanoparticles in various proportions. The particles have sizes ranging from 5 to 10 nm, and they are homogeneously dispersed in the final materials. A reaction temperature near 250°C results in translucent films that have good mechani...

The effect of support on the performance Pd1Ag10/Al2O3 and Pd1Ag10/CeO2–ZrO2 catalysts in selective hydrogenation diphenylacetylene (DPA) was studied. Characterization catalyst by DRIFTS-CO HRTEM revealed formation a PdAg single-atom alloy (SAA) structure surface nanoparticles, with Pd1 sites isolated Ag atoms. It found that use CeO2–ZrO2 as carrier makes it possible to increase activity Pd1Ag1...

The performances of different promoters (CeO2, ZrO2 and Ce0.5Zr0.5O2 solid solution) modified Pd/SiC catalysts for methane combustion are studied. XRD and XPS results showed that Zr 4+ could be incorporated into the CeO2 lattice to form Zr0.5Ce0.5O2 solid solution. The catalytic activities of Pd/CeO2/SiC and Pd/ZrO2/SiC are lower than that of Pd/Zr0.5Ce0.5O2/SiC. The Pd/Zr0.5Ce0.5O2/SiC catalys...

ZrO2 heterophase structure nanocrystals (HSNCs) were synthesized with tunable ratios of monoclinic ZrO2 (m-ZrO2) to tetragonal ZrO2 (t-ZrO2). The phase mole ratio of m-ZrO2 versus t-ZrO2 in ZrO2 HSNCs was tuned from 40% to 100%. The concentration of the surface hydroxyl groups on m-ZrO2 is higher than that on t-ZrO2. ZrO2 HSNCs have different surface hydroxyl groups on two crystalline phases. T...

A solution-based strategy for fabrication of high dielectric constant (κ) nanocomposites for flexible organic field effect transistors (OFETs) has been developed. The nanocomposite was composed of a high-κ polymer, cyanoethyl pullulan (CYELP), and a high-κ nanoparticle, zirconium dioxide (ZrO2). Organic field effect transistors (OFETs) based on neat CYELP exhibited anomalous behavior during dev...