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

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.

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

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.


2020 ◽  
Vol 12 (42) ◽  
pp. 47389-47396 ◽  
Author(s):  
Dinithi Rathnayake ◽  
Inosh Perera ◽  
Alireza Shirazi-Amin ◽  
Peter Kerns ◽  
Shanka Dissanayake ◽  
...  

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 14
Author(s):  
Hossein Ghafuri ◽  
Peyman Hanifehnejad ◽  
Zeynab Rezazadeh ◽  
Afsaneh Rashidizadeh

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.


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 747
Author(s):  
Mahashanon Arumugam ◽  
Chee Keong Goh ◽  
Zulkarnain Zainal ◽  
Sugeng Triwahyono ◽  
Adam F. Lee ◽  
...  

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.


2021 ◽  
Vol 894 ◽  
pp. 45-49
Author(s):  
Rosanna Viscardi ◽  
Vincenzo Barbarossa ◽  
Raimondo Maggi ◽  
Francesco Pancrazzi

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.


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