The invention discloses an S-1 full-
silicon molecular sieve and a preparation method thereof as well as application of the S-1 full-
silicon molecular sieve in
caprolactam preparation. The S-1 full-
silicon molecular sieve is prepared by the method comprising the following steps: (1) synthesizing a tetrapropylammonium
hydroxide template agent; and (2) synthesizing a molecular
sieve: carrying out a reaction on tetrapropylammonium
hydroxide liquor and tetraethoxysilane and
ethanol, filtering, washing with deionized water,
drying reaction liquid,
roasting, so as to obtain molecular
sieve raw
powder; adding silica
sol,
polyethylene glycol 2000, and stronger
ammonia water,
sesbania powder and
activated carbon powder in the molecular
sieve raw powder, kneading in a kneader, then carrying out
extrusion;
roasting, immersing the roasted product in a NH3-NH3NO3 mixing solution and a
hydrofluoric acid solution respectively, washing with deionized water,
drying,
roasting again so as to obtain the S-1 full-silicon molecular sieve. In the invention, the template agent is cheap; the conversion rate of the
cyclohexanone and selectivity of the
caprolactam are extremely high; a catalyst can be easily and fast regenerated; and the use of concentrated sulphuric acid is avoided, thus the S-1 full-silicon molecular sieve and the preparation method thereof are environment-friendly.