Zeolite synthesis by simulation of their natural formation conditions: from macroscopic to nanosized crystals

A successful route to prepare zeolites with controlled crystal size from the millimeter range down to nanometer scale by simulating the natural formation conditions is presented. Water is used as the solution and reaction medium at high temperatures and pressures (T=120–400°C, p=1 kbar); aluminosilicate glasses with identical chemical composition as the zeolite products are used as precursors. The synthesis of heulandite is reported as representative example.