نتایج جستجو برای: catalyst activity
تعداد نتایج: 1169846 فیلتر نتایج به سال:
so42-/zno-tio2 catalyst was prepared by sulfating zno-tio2 powders with h2so4 solution. the catalyst was characterized by xrd, ir and hammett indicator. the catalyst showed strong acidity(h0 ≦-16.0). the optimum conditions are found that the calcination temperature is 823k and the soaked consistency of h2so4 is 1 mol/dm3. then so42-/zno-tio2 was applied as the catalyst in the catalytic synthesi...
nanocrystalline sio2–hclo4, as a newly reported catalyst, has been used as an efficient and reusable catalyst for the synthesis of pyrimidine derivatives. the procedure can be successfully applied to the efficient synthesis of mono substituted pyrimidine derivatives, using triethyl orthoformate, ammonium acetate, methyl ketone derivatives. in practice, this method is a combination of a satisfac...
A novel silica catalyst was synthesized by evaporation-induced self-assembly (EISA) method and tested for the catalytic selective hydrolysis of cellulose to glucose. This silica catalyst exhibited a higher catalytic activity than other oxides prepared by the same method, such as ZrO2, TiO2, and Al2O3. Using silica as a catalyst, cellulose was selectively hydrolyzed into glucose with a glucose y...
the catalyst pt-ta supported on 7-alumina was prepared by impregnation with solution containing compoundsof ii21k1.0. and ta205 the pt concentration was kept constant at 0.2 vet% while the concentration of thetantalum was 0,4 wt%. the activity and selectivity of catalyst were determined under conditions at 450-500 °cand 15-30 atm.. with molar ratio h2/c[h,e5 and wh=1.5ml/h for converted n-hepta...
A novel heterogeneous Pd/polymer catalyst containing co-catalytic functional groups catalyses the direct alkenylation of anisole with ethyl trans-cinnamate under oxygen. The properties of the polymeric catalyst were compared to other immobilised catalysts. The activity of the polymeric catalyst typically increased with temperature and oxygen pressure exhibiting the optimal activity up to 100 TO...
A heterogeneous catalyst containing manganese Schiff base complex (derived from 2,4-dihydroxybenzadehyde and 1,2-phenylenediamine) is produced by covalent anchoring in MCM-41 matrix. The synthesized catalyst was characterized by X-ray diffraction pattern (XRD), inductivity coupled plasma (ICP), Fourier transform infrared (FT-IR) spectroscopy, N2 sorbtion-desorbtion isotherm and by tr...
an efficient method for the friedel–crafts acylation of a wide range of aromatic compounds in good to excellent yields under solvent-free conditions, using iron zirconium phosphate (zpfe) was investigated. the catalyst is easy to prepare and shows interesting catalytic properties. the catalyst was characterized by some instrumental techniques such as xrd, icp-oes, sem and tem. a wide variety of...
A new method for catalyst deposition on the inner walls of capillary microreactors is proposed which allows exact control of the coating thickness, pore size of the support, metal particle size, and metal loading. The wall-coated microreactors have been tested in a selective hydrogenation reaction. Activity and selectivity reach values close to those obtained with a homogeneous Pd catalyst. The...
msu-s mesoporous catalyst with [sio2]/[al2o3] ratio of 55 was synthesized using tetrapropylammonium hydroxide (tpaoh) as a structure directing agent and hexadecyltrimethylammonium bromide (ctab) as a surfactant. the catalytic activity of the calcined sample was evaluated for the dehydration of methanol to dimethyl ether (dme) in a vertical fixed bed microreactor at a weight hurly space velocity...
a powerful and convenient reaction procedure for the c-n coupling reaction (the buchwald-hartwig reaction), yielding products of n-arylanilines and n-arylamines in both conventional heating and microwave irradiation has been reported. the protocol utilizes a stable and new supper ferromagnetic nanoparticle chelating n-heterocyclic dicarbene palladium(ii) complex (pd-nhc) as catalyst which helps...
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