Zirconium oxide, mesoporous

The lamellar form of mesoporous zirconium oxide was prepared using dodecylamine (DA) as the surfactant. In a typical synthesis zirconium isopropoxide (0.01 mol) was added to a solution of the dodecylamine (DA) (0.03 mol) in propan-l-ol... 

Both aluminum oxide and zirconium oxide are catalytically interesting materials. Pure zirconium oxide is a weak acid catalyst and to increase its acid strength and thermal stability it is usually modified with anions such as phosphates. In the context of mesoporous zirconia prepared from zirconium sulfate using the S+X I+ synthesis route it was found that by ion exchanging sulfate counter-anions in the product with phosphates, thermally stable microporous zirconium oxo-phosphates could be obtained [30-32]. Thermally stable mesoporous zirconium phosphate, zirconium oxo-phosphate and sulfate were synthesized in a similar way [33, 34], The often-encountered thermal instability of transition metal oxide mesoporous materials was circumvented in these studies by delayed crystallization caused by the presence of phosphate or sulfate anions. 

Kleitz et al. (2002), Krivoruchko et al. (2001) TEM, TGA Zirconium oxophosphate Mesoporous structuring, template removal + + n.a Oxidative template removal, phase formation... 

Chen H. R., Shi J. L., Yu J., Wang L. Z. and Yang D. S., Synthesis of titanium-doped ordered porous zirconium oxide with high-surface-area, Microporous and Mesoporous Materials 39 (2000) pp. 171-176. 

Mesoporous yttrium zirconium oxide or mesoporous cerium oxide anodes and a mesoporous lanthanum strontium manganate cathode constructed from nanocrystallites of these materials organized by a templating mesophase can be used in solid-oxide fuel cells. Mesoporous TiCU has a potential application in dye-sensitized solar cells. 

Triflic acid-functionalized Zr-TMS (zirconium oxide with a mesostructured framework TMS, transition metal oxide mesoporous molecular sieves) have been extensively studied by Chidambaram et alP by the use of a variety of spectroscopic methods including DD/MAS NMR. The observed chemical shift of ca. 119 ppm and a Jcf coupling of ca 310 Hz showed that the triflic acid remained intact on the catalyst framework. 

Ozin and coworkers recently extended the supra-molecular I S+ assembly into the synthesis of binary mesoporous yttrium oxide-stabilized-zirconium oxide materials.These materials were synthesized by a modified sol-gel method under basic conditions, where zirconium ethoxide and yttrium acetate were used as the precursors for the transition metal oxides, and CTAB was used to form the supramolecular templates. The use of ethylene glycol with coordinating capability as a cosolvent may play a role in controlling the hydrolysis rate and solubility of zirconium(IV) and yttrium(III). This synthesis strategy is similar to that of so-called polymerizable-complex method, which was widely used to prepare multicomponent single-phase oxides. The yttrium content in these binary materials can be tuned from 12-56 wt%, and no phase segregation of yttrium and zirconium oxides was observed. These materials could be applied in designing new solid oxide fuel-cell electrode materials. 

Blin. J.L. Gigot. L. Leonard. A. Su. B.L. Mesoporous zirconium oxides An investigation of physical-chemical synthesis parameters. Stud. Surf Sci. Catal. 2002,141. 257. 

Wang. Y.Q. Yin. L.X. Palchik, O. Hacohen, Y.R. Koltypin. Y. Gedanken. A. Rapid synthesis of mesoporous yttrium-zirconium oxides with ultrasound irradiation. Langmuir 2001. 77, 4131. 

The acidity of the HPA was compared with several tungsten- and molybdenum-based materials such as bulk tungsten trioxide, monolayer supported tungsten species, nanoparticulate mesoporous tungsten-zirconium oxide, and Keggin heteropolyacids. 

Subsequently, it was found that the surfactant in the synthesis system can modify the mesoporous textural properties but does not affect the self-formation of the meso-macroporous hierarchy. Zirconium oxides with the similar meso-macropo-rous structure could also be synthesized via the self-formation phenomenon in the absence of a surfactant [131]. The resulting hierarchically meso-macroporous zir-coniiun oxides are mainly tens of micrometers in size with a regular array of parallel or funnel-like macrochannek of 300-800 nm in diameter. The macropore walls are constmcted from mesochannels (around 2.0 nm) with a wormhole-like array. These materials obtained via this self-formation phenomenon present high surface area and pure crystalline phases in meso-macroporous structures. 

Choi J, Ide A, Traong YB, Kyratzis IL, Caruso RA (2013) High surface area mesoporous titanium-zirconium oxide nanofibrous web a heavy metal ion adsoibent. J Mater Chem A l(19) 5847-5853. doi 10.1039/c3ta00030c... 

Mesoporous zirconia (zirconium oxide) materials containing mainly mesopores have been synthesized via sol-gel reactions from zirconinm propoxide nsing urea as a template. The solid was dried, extracted with water to remove urea, calcined at different temperatures and impregnated with trifluoromethanesulfonic acid. The samples thus obtained were extracted with a tnixmre of dichloromethane and diethyl ether using a Soxhlet apparatus in order to remove the loosely adsorbed acid. The solids were characterized by FT-IR, XRD, DTA-TGA, and N2 adsorption-desorption measnrements. The mean pore diameter of the support was higher than 3.7 mn, which increased with the increment of the thermal treatment temperature. At the same time, the specific surface area and the amount of triflic acid attached on the support decreased. The potentiometric titration with n-butylamine indicated that the catalysts present very strong acid sites. The catalytic activity of the prepared catalysts in the esterification of 4-hydroxybenzoic acid w ith propyl alcohol was evaluated. 

Menzies, D. B. Dai, Q. Bourgeois, L. Caruso, R. A. Cheng, Y. B. Simon, G. P. Spiccia, L. 2007. Modification of mesoporous Ti02 electrodes by surface treatment with titanium(IV), indium(III) and zirconium(IV) oxide precursors Preparation, characterization and photovoltaic performance in dye-sensitized nanocrystalline solar cells. Nanotechnology 18 125608. 

Knowles, J.A. Hudson, MJ. Preparation and characterization of mesoporous, high surface area zirconium(IV) oxides. Chem. Commun. 8995, 2083. 

Mesoporous oxides from elements other than sihca have been reported as early as 1994. Cieslaetal. [169] found that metals such as Sb, Fe, Zn, Pb,W, and Mo also form mesoporous oxides. However, many of the mesophases obtained were lamellar and were not porous after template removal (calcination). Antonelli and Ying reported the transformation of titanium, niobium, and tantalum alkoxides into stable mesophases [170]. Subsequently, mesoporous oxides based on zirconium, hafnium, and manganese have been synthesized (for a recent review on these materials see [171]). Bagshaw and Pinnavaia [172] prepared mesoporous alumina with worm-like pores and a specific surface area of more than 400 m g . Mesoporous alumina with surface areas above 700 m g have been reported by Vaudry et al. [173]. 

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