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Ştefănescu, Mircea; Sasca, Viorel; Bîrzescu, M.

doi:10.1023/a:1010165030191

Cited by 17 publications

(6 citation statements)

References 4 publications

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“…The IR spectrum of a solid obtained after calcination of the EG−methanol solution containing Al(NO 3 ) 3 ·6H 2 O at 523 K has carbonyl peaks (1722, 1699, and 1639 cm -1 ), which are similar to carbonyl peaks (1723 and 1695 cm -1 ) of commercial Al 2 (C 2 O 4 ) 3 · n H 2 O (Supporting Information Figure S1). Stefanescu and co-workers have reported a similar reaction in aqueous media, which was similar to the reaction we found in our synthesis of 3DOM LaFeO 3 and ZnFe 2 O 4 . 7a,b The weight loss up to 473 K was ca. 78%, indicating the presence of the desired Al−glyoxylate .…”

Section: Resultssupporting

confidence: 88%

Facile Preparation of Three-Dimensionally Ordered Macroporous Alumina, Iron Oxide, Chromium Oxide, Manganese Oxide, and Their Mixed-Metal Oxides with High Porosity

et al. 2007

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This paper describes a facile method to produce three-dimensionally ordered macroporous (3DOM) alumina, iron oxide, manganese oxide, chromium oxide, and their mixed-metal oxides. An ethylene glycol (EG)-methanol mixed solution of metal nitrates was infiltrated into the void of the colloidal crystal template of a monodispersed poly(methyl methacrylate) (PMMA) sphere. Heating initiated nitrate oxidation of the EG to produce metal glyoxylate salt. Further heating converted the glyoxylate salt to metal oxide and decomposed PMMA which produced the desired 3DOM metal oxides. Two important parameters of this method are clarified in order to produce a well-ordered 3DOM structure in high yield: (1) The nitrate oxidation temperature should be lower than the glass transition temperature of the PMMA. ( 2) The heat produced by oxidative decomposition of the PMMA should effectively be removed. Furthermore, high porosity (66-81%) of the 3DOM materials was confirmed by Hg porosimetry, which can permit facile transport of guest molecules and particles in potential catalysis and filtration.

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Section: Resultssupporting

confidence: 88%

Facile Preparation of Three-Dimensionally Ordered Macroporous Alumina, Iron Oxide, Chromium Oxide, Manganese Oxide, and Their Mixed-Metal Oxides with High Porosity

et al. 2007

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“…Third, the solid materials should be converted to the desired mixed metal oxide without melting. To satisfy these requirements, we have focused on an efficient method of obtaining heterometallic complexes coordinated by glyoxylate ([C 2 H 2 O 4 ] 2- ) as a ligand reported by Stefanescu et al This method consists of low-temperature oxidation (<373 K) of EG to the glyoxylate dianion in aqueous solution by nitrate of certain metals (Cr, Cu, Zn, Ni, Fe). The metal glyoxylates convert to their metal oxide at relatively low temperature (up to 673 K).…”

Section: Resultsmentioning

confidence: 99%

Facile Procedure To Prepare Three-Dimensionally Ordered Macroporous (3DOM) Perovskite-type Mixed Metal Oxides by Colloidal Crystal Templating Method

et al. 2005

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A new facile procedure to prepare three-dimensionally ordered macroporous (3DOM) materials of perovskite-type La 1-x Sr x FeO 3 (x ) 0-0.4) mixed metal oxides by using colloidal crystal templating method is presented. This method can ensure the desired metal ratio throughout the preparation procedure, and the desired single-phase materials can successfully be prepared. Mixed metal nitrates were dissolved in ethylene glycol-methanol mixed solvent and penetrated into the colloidal crystal template of polystyrene spheres. During the calcination process, the mixed metal nitrates react with ethylene glycol and converted to mixed metal glyoxylates in voids of colloidal crystals before the polymer sphere bursts. After removing the sphere template and converting the mixed metal glyoxylates to the mixed metal oxides, the 3DOM materials of the perovskite-type La 1-x Sr x FeO 3 (x ) 0-0.4) mixed metal oxides were obtained, which was characterized on the basis of thermogravimetric-differential thermal analysis, X-ray diffraction, chemical analysis, scanning electron microscopy, and nitrogen adsorption-desorption technique. Furthermore, the advantage of the 3DOM perovskite-type materials for combustion of nanosize carbon, which is a model of particulate matter exhausted from diesel engines, was demonstrated.

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“…Contrasted with ZS-3G, ZS-3G-C showed no characteristic peak of NO 3 – ion centered at 1380 cm –1 but presented some new adsorption bands, such as ν s (CO) at 1311 cm –1 , δ(OH) at 1360 cm –1 , ν s (COO) at 1430 cm –1 , ν as (COO) at 1680 cm –1 , ,, as well as the characteristic δ(OCO) + ν(MO) vibration peak at 780 cm –1 . , These newly appeared adsorption bands suggest that the redox reaction between EG and nitrates occurred and formed carboxylate complex using the conventional drying method during the gels drying process, which was consistent with other literature. ,− Interestingly, these similar results were obtained when modulating the molar ratio of EG/nitrates ≤ 2 in the new developed strategy. Besides NO 3 – at 1380 cm –1 , ZS-3G also produced an additional peak at 880 cm –1 corresponding to the vibration of δ(CH 2 ) in EG, which confirms the presence of NO 3 – and EG in ZS-3G.…”

Section: Resultsmentioning

confidence: 91%

“…The first significant weight loss in the gel samples occurred at 100 °C, which can be ascribed to the evaporation of the physically adsorbed water. The second significant weight loss was observed at 350 °C, which represents the evolution of large amounts of CO 2 and water, originating from the decomposition of carboxylate. , …”

Section: Resultsmentioning

confidence: 99%

Facile and Versatile Sol–Gel Strategy for the Preparation of a High-Loaded ZnO/SiO₂ Adsorbent for Room-Temperature H₂S Removal

Yang¹,

Kou²,

Fan³

et al. 2019

Langmuir

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Preparation of well-dispersed ZnO nanograins is necessary to improve their reactivity toward room-temperature H 2 S removal. However, the challenge to design such a ZnO-based adsorbent with high ZnO loading is yet to be fulfilled. Herein, a facile sol−gel strategy is reported for the preparation of ZnO/SiO 2 adsorbents for efficient H 2 S removal, by innovating a gel-drying method and simultaneously controlling ZnO grain formation through optimizing the molar ratio of ethylene glycol (EG)/nitrates in its precursors. The fabricated adsorbent embedded welldispersed ZnO nanograins, of approximately 10−15 nm, into a SiO 2 matrix (57 wt % ZnO loading) and thus yielded a high H 2 S removal capacity of 108.9 mg S/g sorbent. Therein, EG was used as a modifier for inhibiting the formation of a denser SiO 2 network during the gel drying process and was used as a fuel for promoting the decomposition of nitrates and increasing the surface area of the composites in the subsequent calcination. Modulating the molar ratio of EG/nitrates ≤ 2 in precursors or traditional drying of the gel in an oven should be avoided because these would lead to the oxidation of EG by metallic nitrates and form carboxylate complexes during the gel-drying process. Although the produced ZnO grains had a very small size of less than 5 nm, a layer of monodentate ZnCO 3 impurity was formed on the ZnO surface, which will drastically decrease the reactivity of ZnO toward H 2 S. According to the encouraging results from CuO and Co 3 O 4 , this strategy has proved to be versatile for the preparation of other metal oxide/SiO 2 adsorbents.

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Untitled

Cited by 17 publications

References 4 publications

Facile Preparation of Three-Dimensionally Ordered Macroporous Alumina, Iron Oxide, Chromium Oxide, Manganese Oxide, and Their Mixed-Metal Oxides with High Porosity

Facile Preparation of Three-Dimensionally Ordered Macroporous Alumina, Iron Oxide, Chromium Oxide, Manganese Oxide, and Their Mixed-Metal Oxides with High Porosity

Facile Procedure To Prepare Three-Dimensionally Ordered Macroporous (3DOM) Perovskite-type Mixed Metal Oxides by Colloidal Crystal Templating Method

Facile and Versatile Sol–Gel Strategy for the Preparation of a High-Loaded ZnO/SiO₂ Adsorbent for Room-Temperature H₂S Removal

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Untitled

Cited by 17 publications

References 4 publications

Facile Preparation of Three-Dimensionally Ordered Macroporous Alumina, Iron Oxide, Chromium Oxide, Manganese Oxide, and Their Mixed-Metal Oxides with High Porosity

Facile Preparation of Three-Dimensionally Ordered Macroporous Alumina, Iron Oxide, Chromium Oxide, Manganese Oxide, and Their Mixed-Metal Oxides with High Porosity

Facile Procedure To Prepare Three-Dimensionally Ordered Macroporous (3DOM) Perovskite-type Mixed Metal Oxides by Colloidal Crystal Templating Method

Facile and Versatile Sol–Gel Strategy for the Preparation of a High-Loaded ZnO/SiO2 Adsorbent for Room-Temperature H2S Removal

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Facile and Versatile Sol–Gel Strategy for the Preparation of a High-Loaded ZnO/SiO₂ Adsorbent for Room-Temperature H₂S Removal