Reaction behaviors and kinetics of catalytic oxidation of toluene with different feed flows over Pt/Zr(x)-HMS catalysts with Si/Zr ratio equal to 5, 10, 20 and 35 were investigated over a wide temperature range (200 – 500 oC). Results show that Pt/Zr(x)-HMS performs more easily toluene oxidation. The kinetic data were fitted by the Power-law and Mars–van Krevelen kinetic models. The fitting res...

Different zirconium-doped mesoporous silicas (Zr-KIT-6, Zr-SBA-15, Zr-MCM-41 and Zr-HMS) were synthesized evaluated in the glucose dehydration to 5-hydroxymethylfurfural (HMF). A Si/Zr molar ratio of 5 was chosen for this purpose after optimization parameter KIT-6 support. These materials characterized by using XRD, N2 sorption, TEM, XPS, NH3-TPD pyridine adsorption coupled FTIR spectroscopy. A...

The interaction between active element Zr and W damages the W fibers and the interface and decreases the mechanical properties, especially the tensile strength of the W fibers reinforced Zr-based bulk metallic glass composites (BMGCs). From the viewpoint of atomic interaction, the W-Zr interaction can be restrained by adding minor elements that have stronger interaction with W into the alloy. T...

Pt/Zr(x)-HMS/HZSM-5 catalysts with different ratios of Silicium/Zirconium (denoted as x) were studied for normal heptane reforming at 350-450 °C temperature range. For this purpose, the properties of the catalysts such as X-ray diffraction, X-ray fluorescence, Fourier-transform infrared spectroscopy, Ultraviolet–visible diffuse reflectance spectroscopy, NH3-temperature pro...

Dense W and W-Zr composites reinforced with Sc2O3 particles were produced through powder metallurgy and subsequent spark plasma sintering (SPS) at 1700 °C and 58 MPa. Results showed that the W-1vol.%Zr/2vol.%Sc2O3 composites exhibited optimal performance with the best relative density of up to 98.93% and high Vickers microhardness of approximately 583 Hv. The thermal conductivity of W-Zr/Sc2O3 ...

We present an x-ray pair distribution function (XPDF) analysis and extended x-ray absorption fine structure (EXAFS) data for ZrW2O8 (10-500 K) with a focus on the stiffness of the Zr-O-W linkage. The XPDF is highly sensitive to W-Zr and W-W correlations, but much less so to O-O or W-O correlations. The Zr-W peak in the XPDF data has a weak temperature dependence and, hence, this linkage is rela...

Pt/Zr(x)-HMS/HZSM-5 catalysts with various Si/Zr ratios (as x) were used for investigation of the kinetics of n-heptane reforming process under 350 - 450 oC reaction temperature, 35 to 80 ml min-1 flowing rate of hydrogen and 2 to 5 ml h-1 flowing rate of n-heptane. In the present work, two kinetics (power law and Langmuir - Hinshelwood) models were selected and examined to describe the kinetic...

Permanent modifiers (Zr, W, Ru, Zr–Ru and Zr–W) thermally deposited on platforms inserted in pyrolytic graphite tubes and Pd 1 Mg(NO3)2 conventional modifier mixture have been employed for the determination of cadmium and lead in dissolved environmental, botanic and biological samples by electrothermal atomic absorption spectrometry (ETAAS). Optimum masses and mass ratios of permanent modifiers...