Synthesis of framework-substituted Co-mordenite by dry gel conversion

Abstract

Framework-substituted Co-mordenite zeolite was synthesized by a dry gel conversion (DGC) method, using inorganic raw materials of silica sol, aluminum sulfate, cobalt nitrate and sodium hydroxide. Typical synthesis conditions were Co/SiO2 = 0.01–0.05, SiO2/Al2O3 = 20–50, H2O/SiO2 = 40, Na2O/SiO2 = 0.4 molar ratios, 170 °C, and 3 days. The obtained samples were characterized by X-ray diffraction, UV–vis, scanning electron microscope, and nitrogen sorption technique. The results showed that Co ions were incorporated into the tetrahedral framework structure of mordenite without forming extra-framework Co species. Products obtained by the present all-inorganic systems possessed open micropores and required no traditional high-temperature calcination. The DGC approach also avoided the separation of the final product from solvent phase.