One-Pot Procedure to Synthesize High Surface Area Alumina Nanofibers Using Supercritical Carbon Dioxide

Langmuir ◽  
2010 ◽  
Vol 26 (4) ◽  
pp. 2707-2713 ◽  
Author(s):  
Muhammad B. I. Chowdhury ◽  
Rouhong Sui ◽  
Rahima A. Lucky ◽  
Paul A. Charpentier
Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1962
Author(s):  
Mahboubeh Nabavinia ◽  
Baishali Kanjilal ◽  
Noahiro Fujinuma ◽  
Amos Mugweru ◽  
Iman Noshadi

To address the issue of global warming and climate change issues, recent research efforts have highlighted opportunities for capturing and electrochemically converting carbon dioxide (CO2). Despite metal doped polymers receiving widespread attention in this respect, the structures hitherto reported lack in ease of synthesis with scale up feasibility. In this study, a series of mesoporous metal-doped polymers (MRFs) with tunable metal functionality and hierarchical porosity were successfully synthesized using a one-step copolymerization of resorcinol and formaldehyde with Polyethyleneimine (PEI) under solvothermal conditions. The effect of PEI and metal doping concentrations were observed on physical properties and adsorption results. The results confirmed the role of PEI on the mesoporosity of the polymer networks and high surface area in addition to enhanced CO2 capture capacity. The resulting Cobalt doped material shows excellent thermal stability and promising CO2 capture performance, with equilibrium adsorption of 2.3 mmol CO2/g at 0 °C and 1 bar for at a surface area 675.62 m2/g. This mesoporous polymer, with its ease of synthesis is a promising candidate for promising for CO2 capture and possible subsequent electrochemical conversion.


Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 854 ◽  
Author(s):  
Hanbo Xiao ◽  
Cheng-an Tao ◽  
Yujiao Li ◽  
Xianzhe Chen ◽  
Jian Huang ◽  
...  

Herein, a facile dopamine assisted one-pot synthesis approach is proposed for the preparation of porous carbon with a specific surface area (SSA) up to 2593 m2/g through the direct pyrolysis of a mixture of glucose, NH4Cl, and dopamine hydrochloride (DAH). The glucose is adopted as the carbon source and foaming agent, NH4Cl is used as the blowing agent, and DAH is served as collaborative carbon precursor as well as the nitrogen source for the first time. The effect of dopamine on the component, structure, and SSA of the as-prepared porous carbon materials are systematically studied. The moderate addition of dopamine, which influences the condensation and polymerization of glucose, matches better with ammonium salt decomposition. The SSA of porous carbon increases first and then decreases with the increasing amount of dopamine. In our case, the porous carbon produced with 5 wt% dopamine (PC-5) achieves the maximum SSA of up to 2593 m2/g. Accordingly, it also shows the greatest electrochemical performance. The PC-5 shows a capacitance of 96.7 F/g calculated from the discharge curve at 1 A/g. It also has a good capacitive rate capacity, the specific capacitance can still maintain 80%, even at a high current density of 10 A/g. Moreover, PC-5 exhibits a good cycling stability of 98.1% capacitive retention after 1000 cycles. The proposed method may show promising prospects for preparing porous carbon materials as advanced energy storage materials, storage, and catalyst supports.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1685
Author(s):  
Katarzyna Morawa Eblagon ◽  
Anna Malaika ◽  
Karolina Ptaszynska ◽  
Manuel Fernando R. Pereira ◽  
José Luís Figueiredo

The cascade dehydration of glucose to 5-hydroxymethylfurfural (HMF) was carried out in water over a series of Nb2O5 catalysts, which were derived from the thermal treatment of niobic acid at 300 and 550 °C, under air or inert atmosphere. Amorphous niobic acid showed high surface area (366 m2/g) and large acidity (2.35 mmol/g). With increasing the temperature of the thermal treatment up to 550 °C, the amorphous Nb2O5 was gradually transformed into a pseudohexagonal phase, resulting in a decrease in surface area (27–39 m2/g) and total acidity (0.05–0.19 mmol/g). The catalysts’ performance in cascade dehydration of glucose realized in pure water was strongly influenced by the total acidity of these materials. A remarkable yield of 37% HMF in one-pot reaction in water was achieved using mesoporous amorphous niobium oxide prepared by thermal treatment of niobic acid at 300 °C in air. The best-performing catalyst displayed a total acidity lower than niobic acid (1.69 mmol/g) which afforded a correct balance between a high glucose conversion and limited further conversion of the target product to numerous polymers and humins. On the other hand, the treatment of niobic acid at 550 °C, independently of the atmosphere used during the sample preparation (i.e., air or N2), resulted in Nb2O5 catalysts with a high ratio of Lewis to Brønsted acid sites and poor total acidity. These materials excelled at catalyzing the isomerization step in the tandem process.


2019 ◽  
Vol 10 (33) ◽  
pp. 4611-4620 ◽  
Author(s):  
Ningning Song ◽  
Tianjiao Wang ◽  
Hongyan Yao ◽  
Tengning Ma ◽  
Kaixiang Shi ◽  
...  

Microporous polyimide networks with high surface area and excellent CO2 adsorption performance have been constructed based on cross-linkable linear polyimides through crosslinking reaction.


2020 ◽  
Vol 56 (14) ◽  
pp. 2095-2098 ◽  
Author(s):  
Eri Hayashi ◽  
Yui Yamaguchi ◽  
Yusuke Kita ◽  
Keigo Kamata ◽  
Michikazu Hara

High-surface-area β-MnO2 nanoparticles exhibited high activity for the one-pot oxidative sulfonamidation of thiols to sulfonamides using O2 and NH3.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chikara Tsutsumi ◽  
Souta Manabe ◽  
Susumu Nakayama ◽  
Yuushou Nakayama ◽  
Takeshi Shiono

Abstract This work studied the incorporation of essential bark oil from Thujopsis dolabrata var. hondae, which is known to repel various insects, in poly(L-lactide-ran-δ-valerolactone) [poly(L-LA-ran-VL)] using supercritical carbon dioxide (scCO2). The poly(L-LA-ran-VL) was synthesized by first purifying the monomers by azeotropic distillation with benzene, followed by polymerization with Sn(oct)2 using the same equipment, representing an efficient one-pot process. The copolymerization of L-LA with VL using this technique at a feed ratio of 90/10 mol/mol gave poly(L-LA-ran-VL) (91/9) with a molecular weight of 6.48 × 104 g/mol and a high yield of 74.9%. Products with molecular weights over 5.0 × 104 g/mol were obtained at L-LA feed proportions of 70 to 90%. Impregnation trials were conducted between 40 and 120 °C at 14 MPa for 3 h. The oil content of a 73/27 specimen was found to increase significantly during processing at 100 or 120 °C. During enzymatic degradation with proteinase K, the 91/9 specimen showed the fastest degradation rate. Although the 71/29 sample was slowly hydrolyzed in a phosphate buffer at pH 7.0, the release of oil vapor from this material was slightly higher than that from the 91/9 specimen, and the vapor release rate continuously increased throughout the hydrolysis process.


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