HYDROTHERMAL SYNTHESIS OF NB-SILICATE MOLECULAR SIEVE

摘要

A method of hydrothermally synthesizing Nb-silicate molecular sieve with excellent catalyst performance is provided to produce inorganic crystalline nano-assembly by applying microwave radiation of high functional Nb-silicate molecular sieve as Redox molecular sieve useful in a variety of applications to introduce Nb ions into structure of the sieve. The hydrothermal synthesis method comprises the steps of: hydrothermally reacting niobium silicate at 150 to 200deg.C; and using niobium alkoxideas metal ions in the synthesis. Constitutional composition of a reaction product is Si/Nb ranging from 28 to 36, TPA^+/SiO2 ranging from 0.2 to 0.5 and H2O/SiO2 ranging from 63.4 to 71.8. The Nb-silicate molecular sieve is fabricated by the steps of: feeding TEOS into a container; dropping niobium alkoxide to TEOS; slowly adding 20% TPAOH to the mixture and agitating the solution; leaving the solution for a constant period of time then heating the solution to execute hydration thereof; hydrothermally reacting the solution in a pressurized reactor; washing, filtering the resulting zeolite crystals; drying and baking the zeolite crystals to form Nb-silicate.