Synthesis, characterization and catalytic properties of Cr-containing silica gel

摘要

Chromium-containing silica gel with variable Si/Cr ratios has been synthesized at ambient temperature by a sol-gel method with the addition of different amounts of Cr precursor. A combination of measurements is used to characterize the chromium-containing silica gel. All the analysis indicates following this synthesis route, it is possible to prepare materials without forming extra wall Cr_2O_3. And the results show that polychromate is absent in the silica gel materials, while the Cr (VI) of calcined chromium-containing silica gel is present as a monochromate species. Also, it has high activity for the selective oxidation of styrene, which is analyzed periodically by means of gas chromatograph.