Table 2.

Structural parameters of the Si- and V-Fe-MCM-48 samples with different treatment time.

Time (h)	MCM-48		V-Fe-MCM-48
	d211 (nm)	a0 a (nm)	V/Si a (Molar Ratio)	Fe/Si b (Molar Ratio)	d211 (nm)	a0 a (nm)
0	3.59	8.80	0.0296	0.0066	3.81	9.33
24	3.56	8.72	0.0107	0.0041	3.70	9.06
48	–	–	0.0079	0.0028	3.68	9.01
72	–	–	0.0062	0.0021	3.56	8.72
96	–	–	0.0048	0.0014	–	–

Notes: ^a Unit cell parameter: a₀ = 6^1/2d₂₁₁; ^b ICP results.