نتایج جستجو برای: silica supported hclo4
تعداد نتایج: 230206 فیلتر نتایج به سال:
A facile and efficient synthesis of bis(indolyl)methanes derivatives (3a-u) was reported via a condensation reaction of aldehydes and indole in the presence of by silica-supported-3-(triethoxysilyl) propane-1-ammonium chloride catalysis under solvent free conditions. We studied the reaction in different conditions and optimized. The use of just 0.02 g of (silica gel-ammonium salt) is sufficient...
The methodology involves preparing polyvinyl sulfuric acid as a solid acid by simple mixing ofpolyvinyl alcohol with chlorosulfonic acid in CH2Cl2 at room temperature. The catalytic ability ofthe solid acid was investigated for the facile conversion of benzylic alcohols to the unsymmetricalethers with aliphatic alcohols in the presence of the solid acid. Results show that the solid acid isan ap...
manganese and cobalt salts of para-amino-benzoic acid supported on silica gel as oxidizing catalysts
para-aminobenzoic acid is supported on silica gel via reaction of activated silica gel and p-aminobenzoic acid which is then converted to its manganese and cobalt salts. a mixture of the manganese and cobalt salts of the acid is used to catalyze allylic and benzylic alcohols to their corresponding carbonyl compounds in reasonable yields using oxygen or air. reactions are clean and the catalysts...
A polyethylenimine-impregnated hierarchical silica monolith exhibited significantly higher CO(2) capturing capacity than other silica-supported amine sorbents, and produced a reversible and durable sorption performance.
Recent debates over the active site structure of supported vanadia/silica catalysts have suggested the existence of a surface vanadium peroxo-oxo "umbrella" structure. This study definitively demonstrates with Raman and UV-vis spectroscopy that the surface vanadia peroxo-oxo umbrella-like structure is not present for both hydrated and dehydrated supported vanadia catalysts such as supported van...
Recent observations of the Martian surface by the Phoenix lander and the Sample Analysis at Mars indicate the presence of perchlorate (ClO4-). The abundance and isotopic composition of these perchlorates suggest that the mechanisms responsible for their formation in the Martian environment may be unique in our solar system. With this in mind, we propose a potential mechanism for the production ...
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