Templated synthesis of mesoporous aluminas by graft copolymer and their CO2 adsorption capacities

Jeon, Harim; Ahn, Sung Hoon; Kim, Jong Hak; Min, Yoon Jae; Lee, Ki Bong

doi:10.1007/s10853-011-5330-1

Cited by 10 publications

(5 citation statements)

References 27 publications

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“…Porous alumina is considered to be a good adsorbent for CO 2 gas. [38][39][40][41] Here we compare the equilibrium CO 2 adsorption capacities on the aluminas obtained through different routes and the results are shown in Fig. 13.…”

Section: Co 2 Adsorption Of Mesoporous G-aluminamentioning

confidence: 99%

Facile strategy for synthesis of mesoporous crystalline γ-alumina by partially hydrolyzing aluminum nitrate solution

et al. 2012

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The facile synthesis of mesoporous g-alumina is developed through the partial hydrolysis of Al(NO 3 ) 3 aqueous solution with (NH 4 ) 2 CO 3 without organic surfactants. In this synthesis, the stable NH 4 NO 3 / Al species (AN/Al) hybrid containing Keggin-Al 13 polycations is first prepared, which is the key for the successful formation of mesoporous g-alumina. XRD, 27 Al MAS NMR, TEM, and N 2 adsorption and desorption results demonstrate that the as-prepared AN/Al hybrid can be transformed to g-alumina by treatment at 200 C and exhibit a wormhole-like mesoporous structure with large surface area up to $450 m 2 g À1 , pore volume of $0.3 cm 3 g À1 and narrow pore size distribution peaked at $3.9 nm after completely removing NH 4 NO 3 at 300 C. The obtained mesoporous g-aluminas have high thermal stabilities up to 900 C and excellent hydrothermal stability. The investigation shows that the synergetic effect of NH 4 NO 3 and Al 13 species promotes crystallization of Al species to g-alumina, which may have a unique mechanism distinct from the mesoporous aluminas reported previously. CO 2 adsorption measurements indicate that these mesoporous g-aluminas have a much higher CO 2 adsorption capacity than ordered mesoporous alumina synthesized by the surfactant-templating method and conventional g-alumina derived from aluminum oxyhydroxides. We believe that this research should be useful for providing new insights into the transformation of transition alumina phases and for synthesizing mesoporous g-alumina with promising properties for various chemical applications.

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Section: Co 2 Adsorption Of Mesoporous G-aluminamentioning

confidence: 99%

Facile strategy for synthesis of mesoporous crystalline γ-alumina by partially hydrolyzing aluminum nitrate solution

et al. 2012

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“…Note that three types of OH groups are available on the zirconia-silica surface, which significantly affect CO 2 uptake and the structure formation between those groups and CO 2 [33,34]. These are called terminal, bi-bridged, and tribridged OH groups and can be identified by infrared (IR) spectroscopy [20,21]. It is well-established that these different types of OH groups are available on the zirconia-silica surface, at higher temperatures up to 600 • C. The terminal-OH groups directly attached to zirconium cations react with CO 2 and form hydrogen-carbonate (HCO 3 ) species (see Scheme S1a, Supplementary Information).…”

Section: Co 2 Physisorptionmentioning

confidence: 99%

Zirconium Containing Periodic Mesoporous Organosilica: The Effect of Zr on CO2 Sorption at Ambient Conditions

et al. 2022

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Two series of zirconium-incorporated-periodic-mesoporous-organosilica (Zr–PMO) materials were successfully prepared, via a co-condensation strategy, in the presence of Pluronic P123 triblock copolymer. The first series of Zr–PMO was prepared using tris[3-(trimethoxysilyl)propyl]isocyanurate (ICS), tetraethylorthosilicate (TEOS), and zirconyl chloride octahydrate(ZrCO), denoted as Zr-I-PMO, where I refers to ICS. The second series was synthesized using bis(triethoxysilyl)benzene (BTEE), TEOS, and ZrCO as precursors, named as Zr-B-PMO, where B refers to BTEE. Zr–PMO samples exhibit type (IV) adsorption isotherms, with a distinct H2-hysteresis loop and well-developed structural parameters, such as pore volume, pore width, high surface area, and narrow pore-size distribution. Structural properties were studied by varying the Zr:Si ratio, adding TEOS at different time intervals, and changing the amount of block copolymer-Pluronic P123 used as well as the calcination temperature. Surface characteristics were tailored by precisely controlling the Zr:Si ratio, upon varying the amount of TEOS present in the mesostructures. The addition of TEOS at different synthesis stages, notably, enhanced the pore size and surface area of the resulting Zr-I-PMO samples more than the Zr-B-PMO samples. Changing the amount of block copolymer, also, played a significant role in altering the textural and morphological properties of the Zr-I-PMO and Zr-B-PMO samples. Optimizing the amount of Pluronic P123 added is crucial for tailoring the surface properties of Zr–PMOs. The prepared Zr–PMO samples were examined for use in CO2 sorption, at ambient temperature and pressure (25 °C, 1.2 bar pressure). Zr–PMO samples displayed a maximum CO2 uptake of 2.08 mmol/g, at 25 °C and 1.2 bar pressure. However, analogous zirconium samples, without any bridging groups, exhibited a significantly lower CO2 uptake, of 0.72 mmol/g, under the same conditions. The presence of isocyanurate- and benzene-bridging groups in Zr-I-PMO and Zr-B-PMO samples enhances the CO2 sorption. Interestingly, results illustrate that Zr–PMO materials show potential in capturing CO2, at ambient conditions.

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“…In addition, parameters such as high surface areas, ready ability to form binary or mixed metal oxides and composites, versatile acid-base properties can explain the attention paid to alumina-based catalytic supports [16][17][18][19][20][21]. Alumina was widely applied as an adsorbent for gas [22] and for different organic [23] and inorganic pollutants [24,25], as a ''direct'' catalyst for many chemical reactions [26], but also extensively used as a support for many catalytic materials [27].…”

Section: Introductionmentioning

confidence: 99%

“…This is giving to c-alumina its specific surface properties: high surface area and acidity. Several methods can be used for managing the surface properties of calumina, for example playing with the temperature of calcination [28], the digestion of the aluminum hydroxide precursor [29], or the incorporation of a template [22,30]. The acidity of c-alumina is a very crucial parameter that plays an effective role in many catalytic reactions as isomerization [31], hydrocracking [32], hydrogenation-dehydrogenation reactions [33], and dehydration [12].…”

Section: Introductionmentioning

confidence: 99%

A new route for the synthesis of self-acidified and granulated mesoporous alumina catalyst with superior Lewis acidity and its application in cumene conversion

et al. 2019

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Self-acidified and granulated mesoporous alumina (SAGMA) with dendritic-like microscopic shape was prepared by a new route that involves: (a) direct dehydration of AlCl 3 (in the presence of capping petroleum wax), and (b) oxi-dation of intermediary AlCl 3 -nanorods. The AlCl 3 solution dispersed in petro-leum wax (capping media) was firstly dehydrated at 100 °C under inert atmosphere for manufacturing anhydrous AlCl 3 -nanorods (length: 50-100 nm; diameter: 5-10 nm). In a second step, this support was oxidized into c-alumina at 300 °C, under air atmosphere. In the course of the manufacturing process, released chlorine was deposited at the surface of the nanorods (more specifically during the oxidation step). The binding of chlorine (5.35%, w/w at the surface) onto c-alumina was demonstrated by both electron dispersive X-ray analysis (SEM-EDX) and Fourier-transformed infrared spectroscopy. Specific surface area reached 230 m 2 g -1 ; the average pore size was 7.8 nm. Material charac-terization was completed by measuring the surface acidity through both tem-perature-programmed desorption and pyridine desorption. The morphology and the phase structure were investigated using scanning electron microscopy and X-ray diffraction analysis, respectively. SAGMA (c-alumina) can be described as a strong Lewis (1.713 mmol g -1 ; i.e., about 93% of total acid sites) and Brønsted acid catalyst supported on a mesoporous structure (self-granular size of 177-250 lm). Cumene conversion (through a dealkylation pathway) was tested on SAGMA: maximum catalytic activity reached 87% at 300 °C. The conversion is highly selective: the reaction produces benzene and only traces of ethylbenzene (mass fraction below 4% compared to benzene). Apart from this good catalytic efficiency, the material is characterized by its strong stability in terms of both catalytic activity (loss less than 2%, for optimum conditions) and surface acidity (loss less than 3%), even for long reaction times (i.e., 24 h) under severe conditions (i.e., T 300 °C). This new material, easily manufactured, is characterized by high efficiency and selectivity in cumene conversion into benzene, associated with high acidity and good stability

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Templated synthesis of mesoporous aluminas by graft copolymer and their CO2 adsorption capacities

Cited by 10 publications

References 27 publications

Facile strategy for synthesis of mesoporous crystalline γ-alumina by partially hydrolyzing aluminum nitrate solution

Facile strategy for synthesis of mesoporous crystalline γ-alumina by partially hydrolyzing aluminum nitrate solution

Zirconium Containing Periodic Mesoporous Organosilica: The Effect of Zr on CO2 Sorption at Ambient Conditions

A new route for the synthesis of self-acidified and granulated mesoporous alumina catalyst with superior Lewis acidity and its application in cumene conversion

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