نتایج جستجو برای: vanadium oxide catalyst
تعداد نتایج: 222343 فیلتر نتایج به سال:
The water-splitting reaction provides a promising mechanism to store renewable energies in the form of hydrogen fuel. The oxidation half-reaction, the oxygen evolution reaction (OER), is a complex four-electron process that constitutes an efficiency bottleneck in water splitting. Here we report a highly active OER catalyst, cobalt vanadium oxide. The catalyst is designed on the basis of a volca...
The vanadium-based catalyst, acts as a homogeneous catalyst for the selective oxidation of various kinds of sulfides with 30% aqueous H2O2. Vanadium-based catalyst was successfully used as the oxygen source for the oxidation of sulfides to sulfoxides for the first time. The sulfoxides were obtained in a good way to high yields without any detectable over-oxidation to sulfones under normal condi...
Introduction Direct methanol fuel cells are very important as a clean, low cost and portable power source because of several environmental problems in traditional energy producing systems. Compared to the hydrogen fueled PEMFCs, direct methanol PEMFCs are more compact and can be used in power portable electric devices. Platinum is the most active electro-catalyst for the electro-oxidation of me...
The information obtained from the characterization of vanadium oxide single crystal surfaces is related to the study of vanadia nanoparticles supported on silica and alumina thin films, model systems for the so-called ‘‘supported monolayer vanadia catalysts’’. It is found that these particles have properties similar to V2O3 surfaces, where the topmost V ions are involved in vanadyl groups and h...
Vanadium phosphorous oxide (VPO) is traditionally manufactured from solid vanadium oxides by synthesizing VOHPO4·0.5H2O (the precursor) followed by in situ activation to produce (VO)2P2O7 (the active phase). This paper discusses an alternative synthesis method based on sol-gel techniques. Vanadium (V) triisopropoxide oxide was reacted with ortho-phosphoric acid in an aprotic solvent. The produc...
Vanadium dioxide (VO(2)) undergoes a sharp metal-insulator transition (MIT) in the vicinity of room temperature and there is great interest in exploiting this effect in novel electronic and photonic devices. We have measured the work function of vanadium dioxide thin films across the phase transition using variable temperature Kelvin force microscopy (KFM). The work function is estimated to be ...
A quadrupole-based mass spectrometer equipped with an electrospray ionization source was used to examine the gas-phase reactivity of various vanadium-oxide cations which mediate the oxidative dehydrogenation (ODH) of small alkenes and alkanes. For ion generation, a solution of V6O7(OMe)12 dissolved in deuterated methanol was subjected electrospray under very harsh conditions to obtain smaller v...
new forms of vanadium oxide nanoporous were fabricated using a simple chemical synthesis method. vanadium pentoxide (v2o5) nanoporous were synthesized by sodium metavanadate as precursor and ethylene glycol as surfactant. the samples were characterized by high resolution transmission electron microscopy (hrtem), field effect scanning electron microscopy (fesem) and x-ray diffraction (xrd), four...
Lithium and Lithium-ion batteries for portable electronic devices and hybrid electric vehicles have gained great importance for energy storage today. However, how to prepare cathode materials with higher energy density, high potentials, and longer cycle life is still a challenge. Compared with commercial LiCoO2, vanadium oxides have higher specific capacity and interesting layered structures, w...
A novel imido-modified SiO2-supported Ti/Mg Ziegler-Natta catalyst for ethylene and ethylene/1-hexene polymerization is investigated. The catalyst is prepared by modification of (SiO2/MgO/MgCl2)TiClx Ziegler-Natta catalysts via supporting vanadium species followed by reaction with p-tolyl isocyanate as imido agents, to get the merits from both the SiO2-supported imido vanadium catalyst and the ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید