One-pot aerobic oxidative sulfonamidation of aromatic thiols with ammonia by a dual-functional β-MnO2 nanocatalyst

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.

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.


NANO ◽  
2015 ◽  
Vol 10 (01) ◽  
pp. 1550005 ◽  
Author(s):  
Yaling Xie ◽  
Aidong Tang ◽  
Huaming Yang

Nanoporous materials Al -MCM-41 with varying Si / Al molar ratios have been successfully synthesized from natural clay mineral halloysite nanotubes (HNTs). Hydrothermal treatment of acid-pretreated HNTs and NaOH solution resulted in the one-step synthesis of final nanoporous products by using surfactant. The effects of Si / Al molar ratios (7.7, 61.0 and 176.5) on the surface area, porosity and degree of structural order of Al -MCM-41 materials have been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), N 2 adsorption–desorption measurements and Fourier transform infrared (FTIR) spectra techniques. The results indicated that Si / Al molar ratio had important effect on the characteristics of nanoporous materials, and Al -MCM-41 with an intermediate Si / Al molar ratio of 61.0 exhibited excellent characteristics with high degree of order, high surface area (S BET ) of 1033 m2/g and pore volume of 0.92 mL/g.


RSC Advances ◽  
2014 ◽  
Vol 4 (103) ◽  
pp. 59175-59184 ◽  
Author(s):  
Jianming Pan ◽  
Heping Gao ◽  
Yunlei Zhang ◽  
Jun Zeng ◽  
Weidong Shi ◽  
...  

This work addressed efficient one-pot conversion of cellulose to 5-hydroxymethylfurfural by porous solid acid in the presence of [Emim]Cl.


Langmuir ◽  
2010 ◽  
Vol 26 (4) ◽  
pp. 2707-2713 ◽  
Author(s):  
Muhammad B. I. Chowdhury ◽  
Rouhong Sui ◽  
Rahima A. Lucky ◽  
Paul A. Charpentier

2019 ◽  
Vol 9 (23) ◽  
pp. 6691-6699
Author(s):  
Hugo Silva ◽  
Patricia Hernandez-Fernandez ◽  
Ane K. Baden ◽  
Henrik L. Hellstern ◽  
Anton Kovyakh ◽  
...  

Supercritical flow technology was used for the one step production of PtPd and PtPdFe nanoparticles supported on high surface area γ-Al2O3.


2012 ◽  
Vol 550-553 ◽  
pp. 3347-3351
Author(s):  
Sha Wang ◽  
Chuan Shan Zhao ◽  
Dai Qi Wang ◽  
Wen Jia Han

Sepiolite has good adsorptivity due to their high surface area and structural channels. During the process of making aluminium silicate fiber paper, inorganic binders retaintion was little because of the smooth surface of aluminium silicate fibers. In this study, sepiolite was used to improve tensile strength of the sheet by increasing inorganic binders retaintion rate through its high adsorptivity. The effect of sepiolite on the tensile strength of alimunium silicate fiber paper was investigated. The results showed that the best mass ratio of aluminium silicate fibers to spiolite was 7:3. Under this condition, the tensile strength of the sheet was 4.79 N•m/g, which increased by 24.2% from the one without sepiolite.


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