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1.
Kinetics and Catalysis - The catalytic properties of a nickel phosphide catalyst supported on silica gel in the reductive amination of carbonyl compounds were studied in a flow reactor using...  相似文献   
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Patents dealing with the production of motor fuel components by hydrodeoxygenation of renewable raw materials based on fatty acid triglycerides are analyzed. Various methods of using sulfide catalysts in hydrodeoxygenation of fatty acid triglycerides and of their mixtures with petroleum fractions are described. The ways to overcome problems that arise in hydrodeoxygenation, based on using sulfide catalysts differing in the active component and support composition, are considered. For example, the use of supported MoS2 catalysts free of Co and Ni ensures the conversion of fatty acid triglycerides along the “direct hydrodeoxygenation” pathway to avoid the formation of carbon oxides and related process problems. The use of sulfide catalysts on zeolite-containing supports allows synthesis of products with improved low-temperature properties due to isomerization (or mild hydrocracking) of С15–С18 alkanes formed by hydrodeoxygenation of fatty acid triglycerides.

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3.
The ferromagnetic resonance (FMR) method in situ is used to study the initial stages of the formation of ? iron oxide nanoparticles deposited on silica gel at temperatures up to 600°C. It is shown that at high-temperature treatment of starting samples obtained by impregnation with an iron(II) sulfate solution, supermagnetic ?-Fe2O3/SiO2 nanoparticles form with a narrow size distribution. An analysis of the FMR data in comparison with the data of other methods enables the formulation of the formation conditions for systems of deposited ?-Fe2O3 nanoparticles without other polymorph impurities.  相似文献   
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The influence of the texture of γ-Al2O3 on the formation of Co(Ni)-Mo catalysts for hydrodesulfurization of the diesel fraction is studied. As shown by low-temperature N2 adsorption, X-ray diffraction, IR spectroscopy of adsorbed molecules, and high resolution electron microscopy (HREM), use of a support with a larger specific surface and a lower total concentration of terminal OH groups makes it possible to prepare more active catalysts. The electron density radial distribution method shows that the finely dispersed cobaltcontaining catalyst in its initial state contains CoMoO4, Al2(MoO4)3, and CoAl2O4, the last two phases being present in trace amounts. After the reaction, this catalyst contains cobalt-doped molybdenum sulfide. According to HREM data, the active phase of the cobalt-containing catalyst consists of layered sulfide association species Co1.3Mo2S3.3, which differ in composition from the bulk phase CoMo2S4. It is assumed that, out of the 1.3 cobalt atoms in Co1.3Mo2S3.3 0.3 Co occurs at the edges of the association species and 1.0 Co is intercalated into their interlayer space, and 0.7 S at the boundary between the association species and the Al2O3 phase is replaced by the corresponding amount of oxygen.  相似文献   
6.
The effect of the heat treatment temperature on the sulfidation and activity of CoMo/Al2O3 catalysts designed for deep hydrodesulfurization of diesel fuel was studied. The catalysts were prepared using citric acid as a chelating ligand. The organic ligands present in the samples heat-treated at 110 and 220°C retard the decomposition of dimethyl disulfide and the formation of the sulfide phase but make the catalyst more active than the samples calcined at higher temperatures.  相似文献   
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An approach is suggested to synthesize the ε-Fe2O3 particles supported on silica with the mean size of few nanometers, narrow size distribution and no admixture of any other iron oxide polymorphs. The facile synthesis is based on the pore filling impregnation method by iron sulfate (II) water solution with the following annealing procedure at ~1173 K. It is shown that the ε-Fe2O3 nanoparticles obtained are stable up to ~1173 K and possess superparamagnetic behavior up to ~870 K.  相似文献   
8.
The effect of the reduction conditions on the physicochemical and catalytic properties of Ni2P/SiO2 catalysts was studied. The catalysts were prepared by impregnating silica with a solution of nickel acetate and diammonium hydrogen phosphate followed by drying, calcination, and temperature-programmed reduction. The Ni2P/SiO2 catalysts were reduced prior to hydrodeoxygenation (HDO) of methyl palmitate in the catalytic reactor (in situ) at temperatures of 550, 600, and 650 °С for 3 h and at 600 °С for 1 and 6 h. The reduction temperature and reduction time were shown to affect the conversion of methyl palmitate, and the optimal reduction conditions of the Ni2P/SiO2 catalysts were found. The Ni2P/SiO2 catalyst synthesized according to a widely used preparation method, including steps of passivation and rereduction at 450 °С in addition to the reduction step, is inferior in activity to the samples prepared in situ.  相似文献   
9.
The effect of the nature of the support modified with the ions of alkaline earth and rare earth elements (Sr, Ba, and La) on the properties of Co-Mo catalysts for the hydrodesulfurization of dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT) was studied using a set of physicochemical and catalytic techniques. It was found that the introduction of modifying additives decreased the surface concentration of Lewis acid sites (LASs) and increased the concentration of basic sites (BSs) in aluminum-containing supports; these changes were more significant upon modification with lanthanum and strontium. The modification affected the distribution and degree of dispersion of Co-Mo-S sulfide packets. It was found that the rate constants of DBT and 4-MDBT conversion increased with decreasing total surface concentration of both LASs and BSs on the support. The highest rate constant of 4,6-DMDBT conversion was reached at an optimum concentration of weak Lewis sites on Co-Mo catalysts, whose support was modified with strontium or barium.  相似文献   
10.
The scope of the electron paramagnetic resonance (EPR) technique in catalysis is often limited because of the presence of the ferromagnetic nanoparticles in many catalytic systems. The present work gives an effective method to discriminate solid-state EPR spectra in the microwave resonance absorption while investigating such systems. The approach is based on the different features of the EPR spectra and ferromagnetic resonance absorption that are simultaneously observed in the system.  相似文献   
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