Engineering Modified Mesoporous Silica Catalysts through Porosity and Surface Acidity Control for Selective Production of DME

2021 ◽  
Vol 894 ◽  
pp. 45-49
Author(s):  
Rosanna Viscardi ◽  
Vincenzo Barbarossa ◽  
Raimondo Maggi ◽  
Francesco Pancrazzi
Keyword(s):  
Mesoporous Silica ◽  
Dimethyl Ether ◽  
Sulfonic Acid ◽  
Pore Diameter ◽  
Solid Acid ◽  
Surface Acidity ◽  
High Surface ◽  
High Surface Area ◽  
Bifunctional Catalysts ◽  
Scanning Electronic Microscopy

DME has been received the attention as a renewable energy due to its thermal efficiencies equivalent to diesel fuel, lower NOx emission, near-zero smoke and non-toxic. DME can be obtained by methanol dehydration over solid acid catalysts or directly from syngas over bifunctional catalysts. The catalytic dehydration of methanol to DME has been widely studied in the literature over pure or modified γ -aluminas (γ-Al2O3) and zeolites. Mesoporous silica has obtained much consideration due to its well-defined structural order, high surface area, and tunable pore diameter. In this work, sulfonic acid and aluminium modified mesoporous silica were synthesized and tested as catalysts for production of dimethyl ether from methanol. The modified silicas were studied utilizing XRD, N2 physisorption, pyridine adsorption, and scanning electronic microscopy. The effects of reaction temperature and water deactivation on the methanol selectivity and conversion to dimethyl ether were investigated. Sulfonic acid modified mesoporous silica showed higher selectivity and stability of DME than that of aluminosilicate. The grafting of mesoporous silica with sulfonic groups displayed much more enhanced hydrothermal stability than Al-MCM-41 and γ-Al2O3.

scholarly journals Mesoporous Porphyrin-Silica Nanocomposite as Solid Acid Catalyst for High Yield Synthesis of HMF in Water

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2519
Author(s):  
Arindam Modak ◽  
Akshay R. Mankar ◽  
Kamal Kishore Pant ◽  
Asim Bhaumik
Keyword(s):  
Sulfonic Acid ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
High Surface ◽  
High Surface Area ◽  
Acid Catalyst ◽  
Acid Sites ◽  
Environmental Research ◽  
Organic Polymer ◽  
High Yield

Solid acid catalysts occupy a special class in heterogeneous catalysis for their efficiency in eco-friendly conversion of biomass into demanding chemicals. We synthesized porphyrin containing porous organic polymers (PorPOPs) using colloidal silica as a support. Post-modification with chlorosulfonic acid enabled sulfonic acid functionalization, and the resulting material (PorPOPS) showed excellent activity and durability for the conversion of fructose to 5-hydroxymethyl furfural (HMF) in green solvent water. PorPOPS composite was characterized by N2 sorption, FTIR, TGA, CHNS, FESEM, TEM and XPS techniques, justifying the successful synthesis of organic networks and the grafting of sulfonic acid sites (5 wt%). Furthermore, a high surface area (260 m2/g) and the presence of distinct mesopores of ~15 nm were distinctly different from the porphyrin containing sulfonated porous organic polymer (FePOP-1S). Surprisingly the hybrid PorPOPS showed an excellent yield of HMF (85%) and high selectivity (>90%) in water as compared to microporous pristine-FePOP-1S (yield of HMF = 35%). This research demonstrates the requirement of organic modification on silica surfaces to tailor the activity and selectivity of the catalysts. We foresee that this research may inspire further applications of biomass conversion in water in future environmental research.

scholarly journals Synthesis of high surface area mesoporous silica SBA-15 by adjusting hydrothermal treatment time and the amount of polyvinyl alcohol

2019 ◽  
Vol 17 (1) ◽  
pp. 963-971
Author(s):  
Ridhawati Thahir ◽  
Abdul Wahid Wahab ◽  
Nursiah La Nafie ◽  
Indah Raya
Keyword(s):  
Mesoporous Silica ◽  
Surface Area ◽  
Hydrothermal Treatment ◽  
Pore Volume ◽  
Pore Diameter ◽  
High Surface ◽  
High Surface Area ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray

AbstractThe high surface area of mesoporous silica SBA-15 has been synthesized successfully by hydrothermal treatment with direct addition of PVA, triblock copolymer (P123) as a direct structure agent and tetraethyl orthosilicate (TEOS) as a precursor. The mesoporous silica SBA-15 have been characterized with nitrogen physisorption, scanning electron microscopy, Fourier transformed infrared spectroscopy, and x-ray diffraction. Measurement of nitrogen sorption indicated that with the addition of PVA, the surface area is increased but the pore volume and pore diameter is not significantly. The short time of hydrothermal treatment (20 h) and using x-ray diffraction, showed that the morphological structure of silica SBA-15 can be changed to a orthorhombic crystal system. The result of the FTIR and SEM-EDX characteristic indicated the functional groups and morphology of the SBA-15 with a narrow pore size distribution. The BET method has exhibited the largest surface area 1726 m2/g, pore volume 1.4 cm3/g, and pore diameter 3.2 nm. It can be suggested that the silica mesoporous SBA-15 will have potential application prospect in catalysis, storage, and adsorbent.

scholarly journals Hierarchical HZSM-5 for Catalytic Cracking of Oleic Acid to Biofuels

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 747
Author(s):  
Mahashanon Arumugam ◽  
Chee Keong Goh ◽  
Zulkarnain Zainal ◽  
Sugeng Triwahyono ◽  
Adam F. Lee ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Solid Acid ◽  
High Surface ◽  
High Surface Area ◽  
Acid Catalyst ◽  
Hierarchical Network ◽  
Waste Oil ◽  
Acid Catalyzed ◽  
Zeolite Seeds ◽  
20 Nm

Solid acid catalyzed cracking of waste oil-derived fatty acids is an attractive route to hydrocarbon fuels. HZSM-5 is an effective acid catalyst for fatty acid cracking; however, its microporous nature is susceptible to rapid deactivation by coking. We report the synthesis and application of hierarchical HZSM-5 (h-HZSM-5) in which silanization of pre-crystallized zeolite seeds is employed to introduce mesoporosity during the aggregation of growing crystallites. The resulting h-HZSM-5 comprises a disordered array of fused 10–20 nm crystallites and mesopores with a mean diameter of 13 nm, which maintain the high surface area and acidity of a conventional HZSM-5. Mesopores increase the yield of diesel range hydrocarbons obtained from oleic acid deoxygenation from ~20% to 65%, attributed to improved acid site accessibility within the hierarchical network.

scholarly journals Bifunctional acid–base mesoporous silica@aqueous miscible organic-layered double hydroxides

RSC Advances ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 3749-3754 ◽  
Author(s):  
Hongri Suo ◽  
Haohong Duan ◽  
Chunping Chen ◽  
Jean-Charles Buffet ◽  
Dermot O'Hare
Keyword(s):  
Mesoporous Silica ◽  
Pore Size ◽  
Layered Double Hydroxides ◽  
High Surface ◽  
High Surface Area ◽  
Core Shell ◽  
Acid Base ◽  
Double Hydroxides ◽  
Hierarchical Morphology ◽  
Size And Structure

Core@shell materials which exhibit hierarchical morphology with ultra high surface area and controllable pore size and structure have been synthesised.

Recovery of high surface area mesoporous silica from waste hexafluorosilicic acid (H2SiF6) of fertilizer industry

2010 ◽  
Vol 173 (1-3) ◽  
pp. 576-580 ◽  
Author(s):  
Pradip B. Sarawade ◽  
Jong-Kil Kim ◽  
Askwar Hilonga ◽  
Hee Taik Kim
Keyword(s):  
Mesoporous Silica ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Fertilizer Industry

Zirconium Phosphate with a High Surface Area as a Water-Tolerant Solid Acid

2004 ◽  
Vol 94 (1/2) ◽  
pp. 45-47 ◽  
Author(s):  
Yuichi Kamiya ◽  
Shoko Sakata ◽  
Yusuke Yoshinaga ◽  
Ryuichiro Ohnishi ◽  
Toshio Okuhara
Keyword(s):  
Surface Area ◽  
Zirconium Phosphate ◽  
Solid Acid ◽  
High Surface ◽  
High Surface Area

Synthesis and CO Oxidation Catalytic Character of High Surface Area Ruthenium Dioxide Replicated by Cubic Mesoporous Silica

2005 ◽  
Vol 34 (3) ◽  
pp. 390-391 ◽  
Author(s):  
Weihua Shen ◽  
Jianlin Shi ◽  
Hangrong Chen ◽  
Jinlou Gu ◽  
Yufang Zhu ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Co Oxidation ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Ruthenium Dioxide ◽  
Cubic Mesoporous

scholarly journals Catalytic Performance of SBA-15-Supported Poly (Styrenesulfonic Acid) in the Esterification of Acetic Acid with n-Heptanol

2020 ◽  
Vol 10 (17) ◽  
pp. 5835
Author(s):  
Abdulaziz Ali Alghamdi ◽  
Yahya Musawi Mrair ◽  
Fahad A. Alharthi ◽  
Abdel-Basit Al-Odayni
Keyword(s):  
Acetic Acid ◽  
Sulfonic Acid ◽  
Active Sites ◽  
Structural Characteristics ◽  
High Surface ◽  
High Surface Area ◽  
Reaction Times ◽  
Hydrophobic Surface ◽  
Catalytic Performance ◽  
Catalyst Load

A polystyrene sulfonic acid-functionalized mesoporous silica (SBA-15-PSSA) catalyst was synthesized via an established multistep route, employing 2-bromo-2-methylpropionyl bromide as initiator of atom transfer radical polymerization. Fourier-transform infrared spectroscopy, thermogravimetric/differential thermal, Brunauer–Emmett–Teller, and transmission electron microscopy analyses revealed outstanding structural characteristics of the catalyst, including highly ordered mesopores, high surface area (726 m2/g), and adequate estimated concentrations of active sites (0.70 mmol H+/g). SBA-15-PSSA’s catalytic performance was evaluated in the esterification of acetic acid and n-heptanol as a model system at various temperatures (50–110 °C), catalyst loads (0.1–0.3 g), and reaction times (0–160 min). The conversion percentage of acetic acid was found to increase with the temperature, catalyst load, and reaction time. Furthermore, results indicated a fast conversion in the first 20 min of the reaction, with remarkable conversion values at 110 °C, reaching 86%, 94%, and 97% when the catalyst load was 0.1, 0.2, and 0.3 g, respectively; notably, at this temperature, 100% conversation was achieved after 60 min. At 110 °C, the reaction conducted in the presence of 0.3 g of catalyst displayed more than 6.4 times the efficiency of the uncatalyzed reaction. Such activity is explained by the concomitant presence in the polymer of strong sulfonic acid moieties and a relatively high hydrophobic surface, with adequate numbers of active sites for ester production.

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