the nanoparticles of ni–si mixed oxides were prepared by co-precipitation method using nickel nitrate; ni(no3)2 6h2o and tetraethylorthosilicate (teos). the products were characterized by x-ray diffraction (xrd), transmission electron microscopy (tem), and hydrogen temperature program reduction (h2-tpr). the results revealed that ni–si mixed oxides particles were obtained with average particle ...

the nanoparticles of ti-si mixed oxides (ntso) with rutile structure were prepared by sol-gel method in a mixture of alcohol and water as solvent. the solid product was characterized by xrd, ftir, sem, tem, uv, tga and laser raman spectroscopy. the catalytic activity of ntso (5-10 nm) was investigated in the epoxidation of cis stilbene, trans stilbene, and norbornene by using oxidants such as t...

the no removal over oxide sorbents (k2o/al2o3 , cao/al2o3 and bao/al2o3) at a loading of up to 25 wt.% was investigated using a synthetic diesel exhaust gas containing  1,000 ppm no, 1000 ppm iso-butane (i-c4h10), 8% o2 and n2 balance. the reactor was operated  at 250 oc to 450 oc for the activity study. no was effectively stored (removal efficiencies between 30-60 %) as nitrate under experimen...

The nanoparticles of Ni–Si mixed oxides were prepared by co-precipitation method using nickel nitrate; Ni(NO3)2 6H2O and tetraethylorthosilicate (TEOS). The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and hydrogen temperature program reduction (H2-TPR). The results revealed that Ni–Si mixed oxides particles were obtained with average particle ...

Carbon nanotubes (CNTs) were prepared by the catalytic chemical vapor deposition of C2H2 at 550°C in 120 minutes using nanoparticles of Ni-Ce-Zr mixed oxides. The CNTs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and Raman spectroscopy. The results revealed that CNTs with diameter of about 45 nm are o...

Cerium–manganese mixed oxides with compositions of Ce0.5Mn0.5O1.75 and Ce0.8Mn0.2O1.9 were prepared by the citric-acid (Pechini) method and their catalytic properties were compared to CeO2 and Mn2O3. The mixed oxides exhibited higher specific rates than either CeO2 or Mn2O3 for oxidation of both methane and nbutane. While XRD measurements of the mixed oxides suggested that the materials had pri...

Pure and mixed lanthanum and cerium oxides were synthesized via a reverse microemulsion-templated route. This approach yields highly homogeneous and phase-stable mixed oxides with high surface areas across the entire range of La:Ce ratios from pure lanthana to pure ceria. Surprisingly, all mixed oxides show the fluorite crystal structure of ceria, even for 10 lanthanum contents as high as 90%. ...

The crystal structure and d.c. electrical conductivity of a series of homogeneous mixed rare-earth oxides in LnPrO3+y (Ln=Y and lanthanide ion) system are reported. It is found that the ionic size of Ln determines the crystal structure of the oxides in this series. LaPrO3+y and CePrO3+y crystallise in the fluorite structure(fcc), whereas the remaining oxides adopt the C-type rare-earth oxide st...