Stability of Y/MCM-48 composite molecular sieve with mesoporous and microporous structures

Peer review under responsibility of The Ceramic Society of Japan and the Korean Ceramic Society.

Figures & data

Fig. 1 Low-angle XRD patterns (A) and high-angle XRD patterns (B) of the samples obtained after crystallization at different temperatures for 36 h.

Fig. 2 Low-angle XRD patterns (A) and high-angle XRD patterns (B) of the samples obtained after crystallization at 120 °C for different times.

Table 1 Surface areas, average pore sizes, total pore volumes and XRD analysis of various samples.

Sample	Surface areas (m^2/g)	Average pore size (nm)	Total pore volume (m^3/g)	d(211) ^a (nm)	a0 ^a (nm)	t^b (nm)
MCM-48	1626	2.45	1.00	3.53	8.65	6.20
Y/MCM-48	864	2.48	0.86	3.81	9.33	6.85
Y/MCM-48-12	739	2.48	0.71	3.76	9.21	6.73
Y/MCM-48-24	702	2.46	0.60	3.68	9.01	6.55
Y/MCM-48-48	676	2.16	0.52	3.58	8.77	6.61
Y/MCM-48-72	226	1.94	0.29	3.24	7.94	–
Y/MCM-48-700	710	2.46	0.62	3.04	7.45	5.48
Y/MCM-48-800	670	2.47	0.51	3.42	–	4.98
Y/MCM-48-900	6	2.57	0.02	3.37	8.38	–
Y/MCM-48-12(A)	621	2.23	0.47	3.32	8.25	6.15
Y/MCM-48-24(A)	489	2.21	0.42	3.62	8.13	6.04
Y/MCM-48-48(A)	410	2.18	0.35	3.56	8.88	5.95
Y/MCM-48-12(B)	388	2.46	0.29	–	8.72	6.42
Y/MCM-48-24(B)	364	2.19	0.24		–	6.53
Y/MCM-48-48(B)	298	1.94	0.23			–

a Values obtained from XRD results.

b Wall thickness = (a₀/3.0919) − (pore size/2).

Fig. 3 XRD patterns of samples obtained after hydrothermal treatment at 100 °C for different times. (A) Low-angle XRD patterns of Y/MCM-48; (B) high-angle XRD patterns of Y/MCM-48; (C) low-angle XRD patterns of MCM-48; (D) high-angle XRD patterns of NaY.

Fig. 4 XRD patterns of the samples obtained after thermal treatment at different temperatures for 4 h. (A) Low-angle XRD patterns of Y/MCM-48; (B) high-angle XRD patterns of Y/MCM-48; (C) low-angle XRD patterns of MCM-48; (D) high-angle XRD patterns of NaY.

Fig. 5 Low-angle XRD patterns (A) and high-angle XRD patterns (B) of the samples obtained after treatment in 1 mol/L HCl solution for different times.

Fig. 6 Low-angle XRD patterns (A) and high-angle XRD patterns (B) of the samples obtained after treatment in 1 mol/L NaOH solution for different times.

Fig. 7 N₂ adsorption–desorption isotherms of the samples obtained after hydrothermal treatment at 100 °C for different times.

Fig. 8 N₂ adsorption–desorption isotherms of the samples obtained after thermal treatment at different temperatures for 4 h.

Fig. 9 N₂ adsorption–desorption isotherms of the samples obtained after treatment in 1 mol/L HCl solution for different times.

Fig. 10 N₂ adsorption–desorption isotherms of the samples obtained after treatment in 1 mol/L NaOH solution for different times.

Fig. 11 SEM images of the samples: (A) NaY zeolite and (B) Y/MCM-48.

Fig. 12 TEM images of the samples. (A) TEM image of the sample after hydrothermal treatment for 48 h; (B) TEM image of the sample after thermal treatment at 800 °C for 4 h; (C) TEM image of the sample after treatment in 1 mol/L HCl solution for 48 h; (D) TEM image of the sample after treatment in 1 mol/L NaOH solution for 48 h.

Fig. 13 TEM image of the Y/MCM-48 sample (A) and EDS spectrum of the microphase in the Y/MCM-48 sample (B). The inset in (A) is the SAED image of microphase.