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Facile synthesis of highly ordered mesoporous alumina with high thermal and hydrothermal stability using zirconia as promoter
Materials Letters 97 (2013) 27–30
Contents lists available at SciVerse ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Facile synthesis of highly ordered mesoporous alumina with high thermal and hydrothermal stability using zirconia as promoter Xiaoyan Wang, Dahai Pan n, Min Guo, Min He, Pengyu Niu, Ruifeng Li n College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, PR China
a r t i c l e i n f o
abstract
Article history: Received 28 June 2012 Accepted 19 January 2013 Available online 25 January 2013
By using zirconia as promoter, a highly ordered mesoporous alumina with extremely high thermal and hydrothermal stability has been synthesized successfully via an evaporation-induced self-assembly (EISA) pathway associated with thermal treatment. In comparison to pure mesoporous alumina, the resultant mesoporous zirconia–alumina nanomaterials maintain the ordered hexagonal mesostructure, narrow pore-size distribution, high BET surface area and pore volume even after thermal treatment at 1000 1C or boiling water treatment for 6 h. Our contribution provides an important approach to synthesize ordered mesoporous Zr–Al nanomaterials with high thermal and hydrothermal stability, which can find potential application for the catalytic applications in the petroleum industry. & 2013 Elsevier B.V. All rights reserved.
Keywords: Porous materials Thermal properties Mesoporous structure Evaporation-induced self-assembly Composite materials
1. Introduction Ordered mesoporous alumina with highly uniform channels, large surface area, narrow pore-size distribution and tunable pore sizes should possess much more excellent properties as catalysts or catalyst supports employed in petroleum refinement, automobile emission control, and others [1–3]. A series of ordered mesoporous alumina materials have been successfully synthesized through the sol–gel process [3–5] or by utilizing the nano-casting method [6,7]. Among the different proposed processes, the EISA pathway proposed by Yuan et al. [4] seems to be the simplest and the fastest to get highly ordered and thermally stable mesoporous alumina. Despite large surface areas and narrow pore-size distributions, the thermal stability of mesoporous alumina synthesized by Yuan is still far from satisfactory. When the thermal treatment temperature is increased to 800 1C, the amorphous phase of alumina begins to transform into g-alumina combined with an obvious decrease in surface areas and pore volume, which seriously constrains its practical application as catalysts or catalyst supports in the petroleum industry. In addition, for applications that require long-lasting exposure of mesoporous alumina to hydrothermal environments, the stability of mesoporous alumina is very important, which remains a great challenge that severely hinders the practical applications of mesoporous amorphous alumina. Here, we report the synthesis of highly ordered mesoporous zirconia–alumina nanomaterials by the improved EISA method.
n
Corresponding authors. Tel./fax: þ86 351 6010121. E-mail addresses: [email protected] (D. Pan), rfl[email protected], [email protected] (R. Li). 0167-577X/$ - see front matter & 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.matlet.2013.01.083
Compared with pure mesoporous alumina, the direct introduction of Zr during the self-assembly can greatly increase the mesostructural ordering and the thermal/hydrothermal stability of mesoporous alumina. Our contribution provides an important approach to synthesize mesoporous zirconia–alumina nanomaterials with ordered structures, and high thermal and hydrothermal stability, which may find important catalytic applications in the petroleum industry.
2. Experimental section Synthesis procedure: In a typical synthesis, 3.2 g of F127 (EO106PO70EO106, EO¼ethylene oxide, PO ¼propylene oxide) was dissolved in 20 mL anhydrous ethanol solution containing 0.8 g of citric acid and 1.6 g of 37 wt% hydrochloric acid. Then, 3.26 g of aluminum isopropoxide and a required amount of zirconium oxychloride (0, 0.53 and 1.03 g) were slowly added to the above solution, simultaneously. After being vigorously stirred at 30 1C for 24 h, the resultant mixture was transferred to a dish and underwent solvent evaporation at 45 1C for 48 h and thermal treatment at 100 1C for 24 h. The final products were calcined at 550 1C for 5 h to remove the template and named as S-0, S-0.1 and S-0.2 according to the molar ratio of Zr/Al. Thermal and hydrothermal stability evaluation: The thermal and hydrothermal stability were investigated by treating calcined samples in air for 1 h at 1000 1C with a temperature ramp of 10 1C min 1 and in a closed bottle at 100 1C for 6 h under static conditions, respectively. Both treatment processes are correspondingly abbreviated as HC and HT.
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X. Wang et al. / Materials Letters 97 (2013) 27–30
Characterization: Powder X-ray diffraction patterns were recorded on a Shimadzu XRD-6000 diffractometer using Ni-filtered Cu Ka (0.154 nm) radiation. Transmission electron microscopy (TEM) experiments were performed on a JEOL 2011 microscope operated at 200 kV. N2 adsorption was conducted on a Quantachrome analyzer.
3. Results and discussion Fig. 1 presents the XRD patterns of calcined mesoporous alumina prepared with or without using zirconia as a promoter before and after the high-temperature treatment at 1000 1C/boiling water treatment for 6 h. It shows that all calcined samples prepared with the modified EISA method exhibit two well-resolved Bragg peaks (Fig. 1A), which, take sample S-0.2 for example, according to the TEM observation of the well-ordered hexagonal arrays along [110] orientation with uniform pore size and wall thickness (Fig. 2A), can be attributed to p6mm hexagonal symmetry. Compared to XRD pattern of S-0, S-0.1 and S-0.2 exhibit relatively higher signal-to-noise ratio in
their XRD patterns and narrower full width at half-maximum (FWHM) as judged from the (100) diffraction peak, suggesting that the multivalent Zr species from the hydrolysis of zirconium oxychloride can participate in and promote the cooperative self-assembly between F127 and aluminum species to construct a uniform framework in which oligomers of both zirconium and aluminum species cross-link together, leading to a remarkably increased mesostructural ordering of alumina. From the intense (100) peak the unit cell parameters of 10.6, 9.8 and 8.8 nm can be calculated for S-0, S-0.1 and S-0.2, respectively. The N2 adsorption–desorption results show that despite calcination S-0 and S-0.2 both exhibit a typical type IV isotherm; compared to S-0, S-0.2 shows a steeper capillary condensation step occurring at a relative pressure (P/P0) ranging from 0.60 to 0.80 (Fig. 3A), corresponding to a narrower pore size distribution (Fig. 3B), which further indicates that the incorporation of Zr can remarkably increase the mesoporous uniform of alumina (Figs. 1 and 2A). For samples S-0 and S-0.2, the surface areas, pore volumes and pore sizes are 252 and 212 m2/g, 0.56 and 0.51 cm3/g, 11.6 and 9.8 nm, respectively (Table 1).
Fig. 1. XRD patterns of calcined (A), high temperature treated (B) and boiling water treated (C) samples.
Fig. 2. TEM images of S-0.2 (A) and S-0.2(HC) (B) viewed along [110] orientation (the inset in B is the corresponding SAED pattern).
X. Wang et al. / Materials Letters 97 (2013) 27–30
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Fig. 3. N2 adsorption isotherms (A) and the corresponding pore size distribution curves (B) of calcined, high temperature treated and boiling water treated samples. For clarity, the isotherms (A) of S-0.2(HT), S-0(HC), S-0.2(HC), S-0 and S-0.2 are offset along the Y-axis by 200, 350, 450, 550 and 700 cm3/g, respectively, and the corresponding pore size distributions curves (B) are offset by 1, 3, 4.5, 6 and 8 cm3/g, respectively.
Table 1 The structural parameters of samples before and after high-temperature thermal and hydrothermal treatment. Sample
d100 (nm)
P (nm)
S (m2/g)
V (cm3/g)
S-0 S-0(HC) S-0(HT) S-0.2 S-0.2(HC) S-0.2(HT)
9.2 – – 7.6 8.3 7.9
11.6 7.6 – 9.8 6.2 4.8
252 165 485 212 187 282
0.56 0.41 0.51 0.51 0.34 0.41
Note: d100 is the d-spacing calculated from the first peak, p is the pore size calculated from the adsorption branch using the BJH method, S is BET surface area, and V is the total pore volume.
It is well known that the addition of suitable additives plays an important role in restraining the crystallization of alumina during the high temperature treatment [8]. From the small-angle XRD patterns of samples treated at 1000 1C (Fig. 1B), it can be seen that different from S-0(HC) and S-0.1(HC), S-0.2(HC) prepared with the addition of a required amount of Zr still displays two well-resolved peaks, indicating that the ordered mesostructure is well maintained. TEM image also confirmed that S-0.2(HC) treated at 1000 1C possesses highly ordered 2D hexagonal mesostructures (Fig. 2B). When the different probe spots were selected, the energy dispersive X-ray analysis (EDX) results show that similar nZr/nAl were observed, which are near 0.2, indicating that almost all Zr species added in the initial reaction mixture have been eventually introduced into the final products with a result of the homogeneous distribution of Zr and Al at the atomic level. Moreover, the selective area electron diffraction (SAED) pattern (the inset in Fig. 2B) of the ordered mesostructure domains of S-0.2(HC) indicates that the mesoporous wall is still amorphous phase, indicating that the introduction of highly distributed Zr can prevent Al atomic diffusion and sinter at high temperature, and further suppresses the formation of g-alumina from the amorphous phase and the subsequent g- to a-alumina phase transition at an elevated temperature. In contrast, for S-0(HC) and S-0.1(HC) prepared without the addition of Zr or with a little addition of Zr, only
a very weak diffraction peak is observed, indicating that the mesostructures of S-0(HC) and S-0.1(HC) have been seriously destroyed and combined with a conversion of mesoporous walls from amorphous phase to the g-alumina phase, which can be validated by the wideangle XRD patterns (the inset in Fig. 1B). This conclusion is further confirmed by the N2 adsorption– desorption measurements (Fig. 3). For S-0.2(HC), its N2 adsorption–desorption curve still maintains a typical IV isotherm with a H1-type hysteresis loop (Fig. 3A), and the pore size distribution curve (Fig. 3B) is still quite narrow, indicating that the hexagonal mesostructure is well-preserved. From Table 1, it can be seen that after high temperature treatment, S-0.2(HC) retained 88.2% of the specific surface area and 66.7% of the pore volume compared to the untreated S-0.2, which is better than those of S-0(HC). On the other hand, compared to the high temperature thermal stability, the low hydrothermal stability is another important factor seriously inhibiting the application of mesoporous amorphous alumina. From the XRD patterns of samples treated in boiling water (Fig. 1C), it can be seen that sample S-0.2(HT) still shows two well-resolved peaks, indicating that the ordered mesostructure is well maintained. In contrast, for S-0(HT) prepared without adding Zr, no diffraction peak can be observed after the same hydrothermal treatment, indicating that the ordered mesostructure of S-0 has collapsed during the hydrothermal treatment. The results of N2 adsorption–desorption also validate the extremely high hydrothermal stability of S-0.2. The pore size distribution curve of S-0.2(HT) is still quite narrow, and the total pore volume decreases only by 19.6%. In contrast, S-0(HT) after the same hydrothermal treatment shows a hysteresis loop without steep capillary condensation step corresponding to an indiscernible pore size distribution (Fig. 3B), indicating inhomogeneous mesopores due to the hydrolysis of Al–O–Al during the hydrothermal treatment process. This forcefully suggests that the incorporation of a required amount of Zr and the formation of Zr–O–Al bonding can act as a support for the inorganic alumina framework and effectively protect the highly ordered mesoporous alumina from hydrolysis and collapsing during the boiling water treatment.
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X. Wang et al. / Materials Letters 97 (2013) 27–30
4. Conclusion Highly ordered mesoporous zirconia–alumina nanomaterials with high thermal and hydrothermal stability have been successfully synthesized via an evaporation-induced self-assembly (EISA) pathway associated with thermal treatment. The ordered mesostructure can be well preserved even after high temperature thermal treatment at 1000 1C or boiling water treatment for 6 h. Our achievements provide new contributions to synthesize zirconia–alumina nanomaterials with highly ordered structures and high stability, which may find important catalytic applications in the petroleum industry.
Acknowledgment This work was financially supported by the National Natural Science Foundation of China (51172154), the China Postdoctoral
Science Foundation (2012M510783), and the Shanxi Province Science Foundation for Youths (2012021006-2).
References [1] Marquez-Alvarez C, Zilkova N, Perez-Pariente J, Cejka J. Catal Rev—Sci Eng 2008;50:222–86. [2] Morris SM, Fulvio PF, Jaroniec M. J Am Chem Soc 2008;130:15210–6. [3] Cai WQ, Yu JG, Anand C, Vinu A, Jaroniec M. Chem Mater 2011;23:1147–57. [4] Yuan Q, Yin AX, Luo C, Sun LD, Zhang YW, Duan WT, et al. J Am Chem Soc 2008;130:3465–72. [5] Dacquin JP, Dhainaut J, Duprez D, Royer S, Lee AF, Wilson K. J Am Chem Soc 2009;131:12896–7. [6] Liu Q, Wang A, Wang X, Zhang T. Chem Mater 2006;18:5153–5. [7] Wu ZX, Li QA, Peng D, Webley PA, Zhao DY. J Am Chem Soc 2010;132:12042–50. [8] Angel GD, Guzmn C, Bonilla A, Torres G, Padilla JM. Mater Lett 2005;59:499–502.
Contents lists available at SciVerse ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Facile synthesis of highly ordered mesoporous alumina with high thermal and hydrothermal stability using zirconia as promoter Xiaoyan Wang, Dahai Pan n, Min Guo, Min He, Pengyu Niu, Ruifeng Li n College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, PR China
a r t i c l e i n f o
abstract
Article history: Received 28 June 2012 Accepted 19 January 2013 Available online 25 January 2013
By using zirconia as promoter, a highly ordered mesoporous alumina with extremely high thermal and hydrothermal stability has been synthesized successfully via an evaporation-induced self-assembly (EISA) pathway associated with thermal treatment. In comparison to pure mesoporous alumina, the resultant mesoporous zirconia–alumina nanomaterials maintain the ordered hexagonal mesostructure, narrow pore-size distribution, high BET surface area and pore volume even after thermal treatment at 1000 1C or boiling water treatment for 6 h. Our contribution provides an important approach to synthesize ordered mesoporous Zr–Al nanomaterials with high thermal and hydrothermal stability, which can find potential application for the catalytic applications in the petroleum industry. & 2013 Elsevier B.V. All rights reserved.
Keywords: Porous materials Thermal properties Mesoporous structure Evaporation-induced self-assembly Composite materials
1. Introduction Ordered mesoporous alumina with highly uniform channels, large surface area, narrow pore-size distribution and tunable pore sizes should possess much more excellent properties as catalysts or catalyst supports employed in petroleum refinement, automobile emission control, and others [1–3]. A series of ordered mesoporous alumina materials have been successfully synthesized through the sol–gel process [3–5] or by utilizing the nano-casting method [6,7]. Among the different proposed processes, the EISA pathway proposed by Yuan et al. [4] seems to be the simplest and the fastest to get highly ordered and thermally stable mesoporous alumina. Despite large surface areas and narrow pore-size distributions, the thermal stability of mesoporous alumina synthesized by Yuan is still far from satisfactory. When the thermal treatment temperature is increased to 800 1C, the amorphous phase of alumina begins to transform into g-alumina combined with an obvious decrease in surface areas and pore volume, which seriously constrains its practical application as catalysts or catalyst supports in the petroleum industry. In addition, for applications that require long-lasting exposure of mesoporous alumina to hydrothermal environments, the stability of mesoporous alumina is very important, which remains a great challenge that severely hinders the practical applications of mesoporous amorphous alumina. Here, we report the synthesis of highly ordered mesoporous zirconia–alumina nanomaterials by the improved EISA method.
n
Corresponding authors. Tel./fax: þ86 351 6010121. E-mail addresses: [email protected] (D. Pan), rfl[email protected], [email protected] (R. Li). 0167-577X/$ - see front matter & 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.matlet.2013.01.083
Compared with pure mesoporous alumina, the direct introduction of Zr during the self-assembly can greatly increase the mesostructural ordering and the thermal/hydrothermal stability of mesoporous alumina. Our contribution provides an important approach to synthesize mesoporous zirconia–alumina nanomaterials with ordered structures, and high thermal and hydrothermal stability, which may find important catalytic applications in the petroleum industry.
2. Experimental section Synthesis procedure: In a typical synthesis, 3.2 g of F127 (EO106PO70EO106, EO¼ethylene oxide, PO ¼propylene oxide) was dissolved in 20 mL anhydrous ethanol solution containing 0.8 g of citric acid and 1.6 g of 37 wt% hydrochloric acid. Then, 3.26 g of aluminum isopropoxide and a required amount of zirconium oxychloride (0, 0.53 and 1.03 g) were slowly added to the above solution, simultaneously. After being vigorously stirred at 30 1C for 24 h, the resultant mixture was transferred to a dish and underwent solvent evaporation at 45 1C for 48 h and thermal treatment at 100 1C for 24 h. The final products were calcined at 550 1C for 5 h to remove the template and named as S-0, S-0.1 and S-0.2 according to the molar ratio of Zr/Al. Thermal and hydrothermal stability evaluation: The thermal and hydrothermal stability were investigated by treating calcined samples in air for 1 h at 1000 1C with a temperature ramp of 10 1C min 1 and in a closed bottle at 100 1C for 6 h under static conditions, respectively. Both treatment processes are correspondingly abbreviated as HC and HT.
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X. Wang et al. / Materials Letters 97 (2013) 27–30
Characterization: Powder X-ray diffraction patterns were recorded on a Shimadzu XRD-6000 diffractometer using Ni-filtered Cu Ka (0.154 nm) radiation. Transmission electron microscopy (TEM) experiments were performed on a JEOL 2011 microscope operated at 200 kV. N2 adsorption was conducted on a Quantachrome analyzer.
3. Results and discussion Fig. 1 presents the XRD patterns of calcined mesoporous alumina prepared with or without using zirconia as a promoter before and after the high-temperature treatment at 1000 1C/boiling water treatment for 6 h. It shows that all calcined samples prepared with the modified EISA method exhibit two well-resolved Bragg peaks (Fig. 1A), which, take sample S-0.2 for example, according to the TEM observation of the well-ordered hexagonal arrays along [110] orientation with uniform pore size and wall thickness (Fig. 2A), can be attributed to p6mm hexagonal symmetry. Compared to XRD pattern of S-0, S-0.1 and S-0.2 exhibit relatively higher signal-to-noise ratio in
their XRD patterns and narrower full width at half-maximum (FWHM) as judged from the (100) diffraction peak, suggesting that the multivalent Zr species from the hydrolysis of zirconium oxychloride can participate in and promote the cooperative self-assembly between F127 and aluminum species to construct a uniform framework in which oligomers of both zirconium and aluminum species cross-link together, leading to a remarkably increased mesostructural ordering of alumina. From the intense (100) peak the unit cell parameters of 10.6, 9.8 and 8.8 nm can be calculated for S-0, S-0.1 and S-0.2, respectively. The N2 adsorption–desorption results show that despite calcination S-0 and S-0.2 both exhibit a typical type IV isotherm; compared to S-0, S-0.2 shows a steeper capillary condensation step occurring at a relative pressure (P/P0) ranging from 0.60 to 0.80 (Fig. 3A), corresponding to a narrower pore size distribution (Fig. 3B), which further indicates that the incorporation of Zr can remarkably increase the mesoporous uniform of alumina (Figs. 1 and 2A). For samples S-0 and S-0.2, the surface areas, pore volumes and pore sizes are 252 and 212 m2/g, 0.56 and 0.51 cm3/g, 11.6 and 9.8 nm, respectively (Table 1).
Fig. 1. XRD patterns of calcined (A), high temperature treated (B) and boiling water treated (C) samples.
Fig. 2. TEM images of S-0.2 (A) and S-0.2(HC) (B) viewed along [110] orientation (the inset in B is the corresponding SAED pattern).
X. Wang et al. / Materials Letters 97 (2013) 27–30
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Fig. 3. N2 adsorption isotherms (A) and the corresponding pore size distribution curves (B) of calcined, high temperature treated and boiling water treated samples. For clarity, the isotherms (A) of S-0.2(HT), S-0(HC), S-0.2(HC), S-0 and S-0.2 are offset along the Y-axis by 200, 350, 450, 550 and 700 cm3/g, respectively, and the corresponding pore size distributions curves (B) are offset by 1, 3, 4.5, 6 and 8 cm3/g, respectively.
Table 1 The structural parameters of samples before and after high-temperature thermal and hydrothermal treatment. Sample
d100 (nm)
P (nm)
S (m2/g)
V (cm3/g)
S-0 S-0(HC) S-0(HT) S-0.2 S-0.2(HC) S-0.2(HT)
9.2 – – 7.6 8.3 7.9
11.6 7.6 – 9.8 6.2 4.8
252 165 485 212 187 282
0.56 0.41 0.51 0.51 0.34 0.41
Note: d100 is the d-spacing calculated from the first peak, p is the pore size calculated from the adsorption branch using the BJH method, S is BET surface area, and V is the total pore volume.
It is well known that the addition of suitable additives plays an important role in restraining the crystallization of alumina during the high temperature treatment [8]. From the small-angle XRD patterns of samples treated at 1000 1C (Fig. 1B), it can be seen that different from S-0(HC) and S-0.1(HC), S-0.2(HC) prepared with the addition of a required amount of Zr still displays two well-resolved peaks, indicating that the ordered mesostructure is well maintained. TEM image also confirmed that S-0.2(HC) treated at 1000 1C possesses highly ordered 2D hexagonal mesostructures (Fig. 2B). When the different probe spots were selected, the energy dispersive X-ray analysis (EDX) results show that similar nZr/nAl were observed, which are near 0.2, indicating that almost all Zr species added in the initial reaction mixture have been eventually introduced into the final products with a result of the homogeneous distribution of Zr and Al at the atomic level. Moreover, the selective area electron diffraction (SAED) pattern (the inset in Fig. 2B) of the ordered mesostructure domains of S-0.2(HC) indicates that the mesoporous wall is still amorphous phase, indicating that the introduction of highly distributed Zr can prevent Al atomic diffusion and sinter at high temperature, and further suppresses the formation of g-alumina from the amorphous phase and the subsequent g- to a-alumina phase transition at an elevated temperature. In contrast, for S-0(HC) and S-0.1(HC) prepared without the addition of Zr or with a little addition of Zr, only
a very weak diffraction peak is observed, indicating that the mesostructures of S-0(HC) and S-0.1(HC) have been seriously destroyed and combined with a conversion of mesoporous walls from amorphous phase to the g-alumina phase, which can be validated by the wideangle XRD patterns (the inset in Fig. 1B). This conclusion is further confirmed by the N2 adsorption– desorption measurements (Fig. 3). For S-0.2(HC), its N2 adsorption–desorption curve still maintains a typical IV isotherm with a H1-type hysteresis loop (Fig. 3A), and the pore size distribution curve (Fig. 3B) is still quite narrow, indicating that the hexagonal mesostructure is well-preserved. From Table 1, it can be seen that after high temperature treatment, S-0.2(HC) retained 88.2% of the specific surface area and 66.7% of the pore volume compared to the untreated S-0.2, which is better than those of S-0(HC). On the other hand, compared to the high temperature thermal stability, the low hydrothermal stability is another important factor seriously inhibiting the application of mesoporous amorphous alumina. From the XRD patterns of samples treated in boiling water (Fig. 1C), it can be seen that sample S-0.2(HT) still shows two well-resolved peaks, indicating that the ordered mesostructure is well maintained. In contrast, for S-0(HT) prepared without adding Zr, no diffraction peak can be observed after the same hydrothermal treatment, indicating that the ordered mesostructure of S-0 has collapsed during the hydrothermal treatment. The results of N2 adsorption–desorption also validate the extremely high hydrothermal stability of S-0.2. The pore size distribution curve of S-0.2(HT) is still quite narrow, and the total pore volume decreases only by 19.6%. In contrast, S-0(HT) after the same hydrothermal treatment shows a hysteresis loop without steep capillary condensation step corresponding to an indiscernible pore size distribution (Fig. 3B), indicating inhomogeneous mesopores due to the hydrolysis of Al–O–Al during the hydrothermal treatment process. This forcefully suggests that the incorporation of a required amount of Zr and the formation of Zr–O–Al bonding can act as a support for the inorganic alumina framework and effectively protect the highly ordered mesoporous alumina from hydrolysis and collapsing during the boiling water treatment.
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X. Wang et al. / Materials Letters 97 (2013) 27–30
4. Conclusion Highly ordered mesoporous zirconia–alumina nanomaterials with high thermal and hydrothermal stability have been successfully synthesized via an evaporation-induced self-assembly (EISA) pathway associated with thermal treatment. The ordered mesostructure can be well preserved even after high temperature thermal treatment at 1000 1C or boiling water treatment for 6 h. Our achievements provide new contributions to synthesize zirconia–alumina nanomaterials with highly ordered structures and high stability, which may find important catalytic applications in the petroleum industry.
Acknowledgment This work was financially supported by the National Natural Science Foundation of China (51172154), the China Postdoctoral
Science Foundation (2012M510783), and the Shanxi Province Science Foundation for Youths (2012021006-2).
References [1] Marquez-Alvarez C, Zilkova N, Perez-Pariente J, Cejka J. Catal Rev—Sci Eng 2008;50:222–86. [2] Morris SM, Fulvio PF, Jaroniec M. J Am Chem Soc 2008;130:15210–6. [3] Cai WQ, Yu JG, Anand C, Vinu A, Jaroniec M. Chem Mater 2011;23:1147–57. [4] Yuan Q, Yin AX, Luo C, Sun LD, Zhang YW, Duan WT, et al. J Am Chem Soc 2008;130:3465–72. [5] Dacquin JP, Dhainaut J, Duprez D, Royer S, Lee AF, Wilson K. J Am Chem Soc 2009;131:12896–7. [6] Liu Q, Wang A, Wang X, Zhang T. Chem Mater 2006;18:5153–5. [7] Wu ZX, Li QA, Peng D, Webley PA, Zhao DY. J Am Chem Soc 2010;132:12042–50. [8] Angel GD, Guzmn C, Bonilla A, Torres G, Padilla JM. Mater Lett 2005;59:499–502.