Hydrogenation of 4-nitrochlorobenzene catalysed by cobalt nanoparticles supported on nitrogen-doped activated carbon

Author(s):  
Juan Jose Villora-Pico ◽  
Ignacio Campello-Gómez ◽  
Juan Carlos Serrano-Ruiz ◽  
M. Mercedes Pastor-Blas ◽  
A. Sepulveda-Escribano ◽  
...  

The hydrogenation of nitroarenes to produce the corresponding amines using dihydrogen as reductant has an important industrial role since it allows to obtain important added-value products. This reaction needs the...

2021 ◽  
Author(s):  
Ance Pļavniece

Studies have shown that high-efficiency micro- and mesoporous activated carbon with high added value can be obtained on the basis of lignocellulose biomass in a three-stage thermochemical process. A methodology has been developed for the synthesis of nitrogen-doped activated carbon by synthesis with dicyandiamide in dimethylformamide suspension as a raw material using wood, its processing residues and wood char.


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3121
Author(s):  
Hosna Ghanbarlou ◽  
Nikoline Loklindt Pedersen ◽  
Morten Enggrob Simonsen ◽  
Jens Muff

The synergy between electrochemical oxidation and adsorption on particle electrodes was investigated in three-dimensional (3D) systems for p-nitrosodimethylaniline (RNO) decolorization and pesticide removal. A comparison was made between granular activated carbon (GAC) and a novel synthesized nitrogen-doped graphene-based particle electrode (NCPE). Experiments on RNO decolorization show that the synergy parameter of the 3D-NCPE system was improved 3000 times compared to the studied 3D-GAC system. This was due to the specific nanostructure and composition of the NCPE material. Nitrogen-doped graphene triggered an oxygen reduction reaction, producing hydrogen peroxide that simultaneously catalyzed on iron sites of the NCPEs to hydroxyl radicals following the electro-Fenton (EF) process. Data showed that in the experimental setup used for the study, the applied cell voltage required for the optimal value of the synergy parameter could be lowered to 5V in the 3D-NCPEs process, which is significantly better than the 15–20 V needed for synergy to be found in the 3D-GAC process. Compared to previous studies with 3D-GAC, the removal of pesticides 2,6 dichlorobenzamide (BAM), 2-methyl-4-chlorophenoxyaceticacid (MCPA), and methylchlorophenoxypropionic acid (MCPP) was also enhanced in the 3D-NCPE system.


RSC Advances ◽  
2015 ◽  
Vol 5 (69) ◽  
pp. 56121-56129 ◽  
Author(s):  
Haoran Yuan ◽  
Lifang Deng ◽  
Xixi Cai ◽  
Shungui Zhou ◽  
Yong Chen ◽  
...  

Nitrogen-doped activated carbon sheets were derived from chitin, which exhibited remarkable activity for ORR and high catalytic activity towards OER.


2021 ◽  
Vol 16 (2) ◽  
pp. 113-121
Author(s):  
Orléans Ngomo ◽  
Joseph Sieliechi ◽  
Etienne Dongo

Avocado is a versatile and valuable product. Its oil is comparable to olive oil in terms of nutritional quality. It can also be used in cosmetics, in particular, in soaps, shampoos and lotions. Despite all these important attributes that avocado has, it is highly perishable and coupled with the lack of farm-to-market roads, a lot of it is lost after harvest during the peak season. The introduction of methods that will transform avocado to products with a long shelf life and added value will go a long way to solving the problem of post-harvest losses and poverty. One of these methods is the production of avocado oil. In addition, in order to reduce the colour of the pigments without altering their quality, discoloration tests were carried out by adsorption on bleaching grounds (a montmorillonite, a kaolinite and activated carbon). The colour intensities of the oils before and after adsorption were determined using two complementary methods: a UV-Vis spectrophotometer and a Konica Minolta spectrophotometer CM-5. The UV-Vis spectrophotometer show that the activated carbon has a best fixing capacity of the pigments; According to the Colorimetric parameters (CIE-Lab) the coordinates L* a* b* that showed brightness (L*) of the avocado oil was half of the olive oil (41.13±0.02 vs 84.85±0.02). The activated carbon was better in fixing the red (a*) (4.99±0.01vs 15.73±0.01 before adsorption) and yellow (b*) (63.71±0.09 vs 70.07±0.09 before adsorption) pigments, while the other two adsorbents have very little influence on the red colour of avocado oil. RésuméL’avocat est un produit versatile et de grande valeur. Son huile est comparable à huile d’olive en terme de qualité nutritionnelle ; elle peut également être utilisée en cosmétique en occurrence dans les savons, champoings et lotions. En pleine saison, l’on fait face à une abondance des avocats dans les zones de production qui sont très souvent enclavées ; c’est ainsi que face aux difficultés de transport et les routes peu praticables pour l’importation, l’on se retrouve en train de perdre de très importantes quantités d’avocats après les récoltes. Or la production d’huile d’avocats permettrait de réduire les pertes post récolte, réduirait le chômage et permettrait de lutter contre la pauvreté après la vente des huiles extraites. De plus, dans le but de réduire les pigments colorés, des tests de décolorations effectués par adsorption sur des terres décolorantes (une montmorillonite en provenance de Maroua, une kaolinite en provenance de Douala et le charbon actif) sont effectués. Les couleurs des huiles mesurées avant et après adsorption à l’aide deux appareils complémentaires : Le spectrophotomètre UV-Vis et du Konica Minolta spectrophotomètre CM-5 montrent. Les analyses spectrophotométriques UV-Vis montrent que c’est le charbon activé qui présente la meilleure adsorption des pigments ; D’après les coordonnées L*a*b*, la clarté de l’huile d’avocat est pratiquement la moitié de celle de l’huile d’olive (41,13±0,02 contre 84,85±0,02), le charbon activé fixe mieux les pigments rouges (a*) (4,99±0,01 contre 15,73±0,01 avant adsorption) et jaunes (b*) (63,71±0,09 contre 70,07±0,09 après adsorption), tandis que les deux autres adsorbants influencent très peu sur la coloration des huiles.


2018 ◽  
Vol 514 ◽  
pp. 281-288 ◽  
Author(s):  
Duihai Tang ◽  
Kuo Li ◽  
Wenting Zhang ◽  
Zhen-An Qiao ◽  
Junjiang Zhu ◽  
...  

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