Tailoring the Pore Sizes of Microporous Pillared Interlayered Clays through Layer Charge Reduction

A F-rich potassium hectorite, [K0.48(2)]inter[Mg2.54(8)Li0.43]oct[Si4]tetO10F2, with a layer charge of x = 0.48 per formula unit (pfu) was synthesized by high temperature melt synthesis. After Mg-exchange, the layer charge could be reduced significantly post synthesis by annealing (250 °C) as confirmed by alkylammonium exchange and cation exchange capacity. By pillaring this new low charge material with Me2DABCO2+ (N,N-dimethyl-1,1-diazabicyclo [2.2.2]octane dication) and Rh(bpy)3 3+ (rhodium-tris-2,2′-bipyridin trication), we observed a remarkable increase in micropore volume and pore diameter by Ar/Ar(l) physisorption measurements. This method allows the tailoring of pore sizes of pillared clays by reducing the layer charge and consequently the pillar density.