Characterization and Stability of Heteropolyacid Catalysts Supported on MCM-41 Materials Synthesized by Ultrasonic Irradiation

2017 ◽  
Vol 68 (1) ◽  
pp. 101-107
Author(s):  
Song Il Kong ◽  
Danuta Matei ◽  
Diana Cursaru ◽  
Vasile Matei ◽  
Dragos Ciuparu
Keyword(s):  
Raman Spectroscopy ◽  
Ultrasonic Irradiation ◽  
Solid Acid Catalyst ◽  
High Surface ◽  
High Surface Area ◽  
Acid Catalyst ◽  
Pore Wall ◽  
Synthesis Methods ◽  
Impregnation Method ◽  
Mcm 41

A series of solid acid catalyst of the Keggin-type 12-phosphotungstic acid, H3PW12O40, supported on ordered mesoporous silica MCM-41 were prepared by a simple and effective impregnation method. MCM-41 supports were synthesized in a relatively short time via a recently reported ultrasonic irradiation method. The synthesis sonication time has been systematically varied in order to investigate its influence on the structural order of the resulting materials. The prepared catalysts were characterized by nitrogen adsorption, X-ray diffraction, Raman spectroscopy and thermogravimetric analysis. The resulting materials exhibited hexagonally ordered meso structure, with high surface area of the order of several hundreds of m2g-1,relatively large pore volumes, with the pore diameter in the range of 2.19 to 2.41 nm and a corresponding pore wall thickness of over 1.67nm. The results have demonstrated that high quality MCM-41 materials can be synthesized via the ultrasonic irradiation in few tens of minutes, much shorter than the conventional synthesis methods. Despite their relatively high loading, all synthesized materials retained the characteristic MCM-41mesoporous structure after impregnation of the heteropolyacid active phase onto the inner pore surface, without crystallization, but preserving the Keggin structure as confirmed by Raman spectroscopy.

scholarly journals Carbon-Based Catalysts for Biodiesel Production—A Review

2020 ◽  
Vol 10 (3) ◽  
pp. 918 ◽  
Author(s):  
Jack Clohessy ◽  
Witold Kwapinski
Keyword(s):  
Heterogeneous Catalysts ◽  
Catalyst Activity ◽  
High Surface ◽  
High Surface Area ◽  
Acid Catalyst ◽  
Biodiesel Production ◽  
Catalyst Characterization ◽  
Synthesis Methods ◽  
And Performance ◽  
Carbon Based

In recent years, a new class of superior heterogeneous acid catalyst for biodiesel production has emerged. These catalysts offer advantages over their predecessors such as high surface area, elevated acid site density, enhanced catalyst activity, good operation stability and relevant economic affordability in an environmentally friendly frame. This review was concerned with carbon-based solid acid (CBAS) catalysts derived from both carbohydrate and pyrolysis products. A series of CBASs with various origins such as D-glucose, sucrose, starch, cellulose and vegetable oil asphalt, converted to char and sulphonated, have been explored as potential heterogeneous catalysts. Catalyst preparation and synthesis methods were briefly summarized. Catalyst characterization and performance for biofuels related reactions were elucidated, identifying potential research applications. Three catalysts in particular were identified as having potential for industrial application and requiring further research.

scholarly journals Mesoporous Crystalline Niobium Oxide with a High Surface Area: A Solid Acid Catalyst for Alkyne Hydration

2020 ◽  
Vol 12 (42) ◽  
pp. 47389-47396 ◽  
Author(s):  
Dinithi Rathnayake ◽  
Inosh Perera ◽  
Alireza Shirazi-Amin ◽  
Peter Kerns ◽  
Shanka Dissanayake ◽  
...  
Keyword(s):  
Surface Area ◽  
Niobium Oxide ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
High Surface ◽  
High Surface Area ◽  
Acid Catalyst

Zinc-Modified MCM-22 as Potential Solid acid Catalyst for Friedel–Crafts Alkylation Reaction

2013 ◽  
Vol 11 (1) ◽  
pp. 407-415 ◽  
Author(s):  
Sharad V. Lande ◽  
A. Sakthivel, ◽  
K. V. V. S. B. S. R. Murthy ◽  
Unnikrishnan Sreedharan ◽  
Jagannath Das ◽  
...  
Keyword(s):  
Solid Acid Catalyst ◽  
High Surface ◽  
High Surface Area ◽  
Acid Catalyst ◽  
Systematic Investigation ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Alkylation Reaction ◽  
Phase Medium ◽  
Alkylation Of Benzene

Abstract In this paper, we report loading of ZnCl2 on microporous medium pore high surface area zeolite, which was achieved by incipient wetness method. The zinc-modified mobil composite material -22 (Zn-MCM-22) was systematically characterized by powder X-ray diffraction, N2 adsorption-desorption analysis, scanning electron microscopy and Fourier transform infrared spectroscopy. The acidity of the materials was studied by temperature programmed desorption of ammonia analysis. The well-characterized Zn-MCM-22 catalyst was investigated for the Friedel–Crafts alkylation of benzene by benzyl chloride in liquid phase medium. A systematic investigation of various operating parameters like effect of different temperature, catalyst loading and reactant molar ratio was carried out. The Zn-MCM-22 found to be promising, further the catalytic activity remains stable over several recycles.

scholarly journals Nanostructured zeolite with brain-coral morphology and tailored acidity: a self-organized hierarchical porous material with MFI topology

CrystEngComm ◽  
2020 ◽  
Vol 22 (38) ◽  
pp. 6275-6286
Author(s):  
Esun Selvam ◽  
Rajesh K. Parsapur ◽  
Carlos E. Hernandez-Tamargo ◽  
Nora H. de Leeuw ◽  
Parasuraman Selvam
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
High Surface ◽  
High Surface Area ◽  
Acid Catalyst ◽  
Acid Sites ◽  
Diffusion Resistance ◽  
Self Organized ◽  
Hierarchical Porous ◽  
Coral Morphology

Nano-zeolite with brain-coral morphology formed by self-organization of ultra-small nanospheres, exhibits micro/meso porosity with high surface area, distributed acid sites, and reduced diffusion resistance making it a promising solid acid catalyst.

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 Sulfonated Graphitic Carbon Nitride (Sg-C3N4): A Highly Efficient Heterogeneous Organo-Catalyst for Condensation Reactions

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 14
Author(s):  
Hossein Ghafuri ◽  
Peyman Hanifehnejad ◽  
Zeynab Rezazadeh ◽  
Afsaneh Rashidizadeh
Keyword(s):  
Chemical Stability ◽  
Carbon Nitride ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
High Surface ◽  
High Surface Area ◽  
Acid Catalyst ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
High Catalytic Activity

Currently, constructing solid acid catalysts with well-defined structures, environmentally benign, with high catalytic activity, easy separation, and high chemical stability is the most important area of industrial and environmental concern. Over the past few decades, porous conjugated polymers have been employed as stable catalyst supports for various organic transformations. Among these materials, graphitic carbon nitride (g-C3N4) has been widely studied in the field of photocatalysis and heterogeneous catalysis, due to its high surface area and great physical and chemical stability. Herein, we report the synthesis of sulfonated graphitic carbon nitride (Sg-C3N4) as an efficient solid acid catalyst for the preparation of various biologically nitrogen-containing heterocyclic compounds under mild reaction conditions.

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 Preparation of the WOX/MCM-41 Solid Acid Catalyst and the Catalytic Performance for Solketal Synthesis

ACS Omega ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 3875-3883
Author(s):  
Yixuan Huang ◽  
Guangcai Zhang ◽  
Qinhui Zhang
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
Mcm 41
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