Preparation of Interlayer-Expanded Zeolite from Lamellar Precursor Nu-6(1) by Silylation

Interlayer-expanded zeolite, IEZ-NSI, has been post-synthesized from a two-dimensional (2D) layered precursor Nu-6(1) (Si/Al ratio = 30 – ∞) by intercalating with diethoxydimethylsilane in hydrochloric acid solution. Ethanol was demonstrated to be a suitable solvent for inducing an effective interlayer pillaring with monomeric silane. IEZ-NSI was revealed to possess a 3D crystalline structure composed of 10-membered ring (MR) channels by using Rietveld crystal structure refinement of the PXRD pattern of IEZ-Nu-6(1)-H (Si/Al = ∞). The 10-MR pores in IEZ-NSI were constructed through the linkages between the pillaring Si atoms and the NSI layers. IEZ-Nu-6(1)-H(Si/Al = ∞) crystallizes in space group P 121/ a 1 (No. 14) with a = 22.9372(4) Å, b = 5.0205(5) Å, c = 13.8209(1) Å, and β = 103.294(22)°. IEZ-NSI with more accessible channels gave a higher catalytic activity in the esterification of acetic acid with ethanol in comparison to Nu-6(2).