UV-visible diffuse reflectance spectroscopy was used to probe the electronic structure and domain size of tungsten oxide species in crystalline isopolytungstates, monoclinic WO3, and dispersed WOx species on ZrO2 surfaces. UV-visible absorption edge analysis, CO2 chemisorption, and Raman spectroscopic results show that three distinct regions of WOx coverage on ZrO2 supports appear with increasi...

The utilization of metal oxide-zeolite catalysts in the syngas-to-olefin reaction is a promising strategy for producing C2–C4 olefins from non-petroleum resources. However, effect crystal phase oxides on catalytic activity these still ambiguous. Herein, typical (ZnO/ZrO2) with different phases (monoclinic (m-ZrO2) and tetragonal (t-ZrO2)) were employed syngas conversion. (ZnO/m-ZrO2+SAPO-34) co...

The structures, processes of shrinkage, and phase composition of the compact system ZrO2-WC, obtained by hot pressing with the transmission of high current, are considered in the article. We found that as a result of compaction, the ZrO2-WC-ceramics have uniform density distribution, with the following optimal mode consolidation values T = 1,350°C, P = 30 MPa and t = 2 min. These conditions all...

zno and zro2 photo catalysts were synthesized by sol-gel auto combustion method. the products were characterized by x-ray diffraction (xrd) and scanning electron microscopy (sem). structural and morphological properties of nano particles were investigated and the average crystalline size of zno and zro2 was obtained 44 and 51 nm, respectively. also, photo catalytic degradation of nitro phenol f...

Sintered samples of monoclinic zirconia (α-ZrO2) have been irradiated at room temperature with 6.0-GeV Pb ions in the electronic slowing down regime. X-ray diffraction (XRD) and micro-Raman spectroscopy measurements showed unambiguously that a transition to the ‘metastable’ tetragonal phase (β-ZrO2) occurred at a fluence of 6.5x10 cm for a large electronic stopping power value (≈ 32.5 MeV μm). ...

The vapour phase selective conversion of glycerol to acetol at normal atmospheric pressure in a fixed-bed micro reactor was investigated over SO4 2 and WOx promoted ZrO2 and M-ZrO2 (M = Al2O3 or TiO2) solid acid catalysts. The investigated sulfate and tungstate ion promoted zirconia-based catalysts were prepared by both coprecipitation and impregnation methods and calcined at 923 K. The synthes...

Zirconia ZrO2 and hafnia HfO2 are leading candidates for replacing SiO2 as the gate insulator in complementary metal-oxide semiconductor technology. Amorphous versions of these materials a-ZrO2 and a-HfO2 can be grown as metastable phases on top of a silicon buffer; while they tend to recrystallize during subsequent annealing steps, they would otherwise be of considerable interest because of th...

A hybrid nanolaminates consisting of Al2O3/ZrO2/alucone (aluminum alkoxides with carbon-containing backbones) grown by atomic layer deposition (ALD) were reported for an encapsulation of organic light-emitting diodes (OLEDs). The electrical Ca test in this study was designed to measure the water vapor transmission rate (WVTR) of nanolaminates. We found that moisture barrier performance was impr...

Some issues such as tunneling, leakage current and light atom penetration through the film are threatening the ultra thin SiO2 be as a good dielectric for future industrial and electronic devices. Moreover, ultra fine and pure ZrO2/CrO2 are also so important in ceramic technologies. We have demonstrated a series of experiments to synthesis ZrO2 as well as CrO2 at low temperature with using sol-...