scholarly journals Critical review on the chemical reduction of nitroaniline

RSC Advances ◽  
2020 ◽  
Vol 10 (32) ◽  
pp. 19041-19058 ◽  
Author(s):  
Muhammad Imran Din ◽  
Rida Khalid ◽  
Zaib Hussain ◽  
Jawayria Najeeb ◽  
Ahsan Sahrif ◽  
...  
Keyword(s):  
Critical Review ◽  
Catalytic Reduction ◽  
Chemical Reduction ◽  
Reducing Agent

Schematic illustration of catalytic reduction of 4-NA in the presence of nanocatalysts and a reducing agent.

scholarly journals Poly(N-isopropylacrylamide-co-methacrylic acid) microgel stabilized copper nanoparticles for catalytic reduction of nitrobenzene

2015 ◽  
Vol 33 (3) ◽  
pp. 627-634 ◽  
Author(s):  
Zahoor H. Farooqi ◽  
Zonarah Butt ◽  
Robina Begum ◽  
Shanza Rhauf Khan ◽  
Ahsan Sharif ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Methacrylic Acid ◽  
Catalytic Reduction ◽  
Aqueous Media ◽  
Activation Parameters ◽  
Reducing Agent ◽  
Different Temperatures ◽  
Entropy Of Activation ◽  
Micro Reactors

Abstract Poly(N-isopropylacrylamide-co-methacrylic acid) microgels [p(NIPAM-co-MAAc)] were synthesized by precipitation polymerization of N-isopropylacrylamide and methacrylic acid in aqueous medium. These microgels were characterized by dynamic light scattering and Fourier transform infrared spectroscopy. These microgels were used as micro-reactors for in situ synthesis of copper nanoparticles using sodium borohydride (NaBH4) as reducing agent. The hybrid microgels were used as catalysts for the reduction of nitrobenzene in aqueous media. The reaction was performed with different concentrations of cat­alyst and reducing agent. A linear relationship was found between apparent rate constant (kapp) and amount of catalyst. When the amount of catalyst was increased from 0.13 to 0.76 mg/mL then kapp was increased from 0.03 to 0.14 min-1. Activation parameters were also determined by performing reaction at two different temperatures. The catalytic process has been discussed in terms of energy of activation, enthalpy of activation and entropy of activation. The synthesized particles were found to be stable even after 14 weeks and showed catalytic activity for the reduction of nitrobenzene.

scholarly journals A Review on the Catalytic Hydrogenation of Bromate in Water Phase

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 365
Author(s):  
Jose Luis Cerrillo ◽  
Antonio Eduardo Palomares
Keyword(s):  
Catalytic Activity ◽  
Ion Exchange ◽  
Reaction Mechanisms ◽  
Catalytic Reduction ◽  
Environmental Concern ◽  
Chemical Reduction ◽  
Catalyst Stability ◽  
Polluted Water ◽  
Water Composition

The presence of bromate in water sources generates environmental concern due to its toxicity for humans. Diverse technologies, like membranes, ion exchange, chemical reduction, etc., can be employed to treat bromate-polluted water but they produce waste that must be treated. An alternative to these technologies can be the catalytic reduction of bromate to bromide using hydrogen as a reducing agent. In this review, we analyze the research published about this catalytic technology. Specifically, we summarize and discuss about the state of knowledge related to (1) the different metals used as catalysts for the reaction; (2) the influence of the support on the catalytic activity; (3) the characterization of the catalysts; (4) the reaction mechanisms; and (5) the influence of the water composition in the catalytic activity and in the catalyst stability. Based on published papers, we analyze the strength and weaknesses of this technique and the possibilities of using this reaction for the treatment of bromate-polluted water as a sustainable process.

An unsaturated metal site-promoted approach to construct strongly coupled noble metal/HNb3O8 nanosheets for efficient thermo/photo-catalytic reduction

Nanoscale ◽  
2017 ◽  
Vol 9 (38) ◽  
pp. 14654-14663 ◽  
Author(s):  
Lijuan Shen ◽  
Yuzhou Xia ◽  
Sen Lin ◽  
Shijing Liang ◽  
Ling Wu
Keyword(s):  
Noble Metal ◽  
Catalytic Reduction ◽  
Reducing Agent ◽  
Capping Agent ◽  
Strongly Coupled ◽  
Metal Site

A Nb4+-promoted approach has been developed to construct Pd/HNb3O8 without a reducing agent or a capping agent. The resulting composites function as efficient thermo/photo-catalysts.

scholarly journals Green Synthesis of Novel Jasmine Bud-Shaped Copper Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Malathi Sampath ◽  
Ramya Vijayan ◽  
Ezhilarasu Tamilarasu ◽  
Abiraman Tamilselvan ◽  
Balasubramanian Sengottuvelan
Keyword(s):  
Copper Nanoparticles ◽  
Isonicotinic Acid ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Acid Hydrazide ◽  
Reducing Agent ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron

Novel jasmine bud-shaped copper nanoparticles were synthesized by a green chemical reduction method using polyvinylpyrrolidone (PVP) as a capping agent, L-ascorbic acid (AA) as a reducing agent as well as antioxidant agent, isonicotinic acid hydrazide (INH) as a reducing agent, and water as a solvent at 60–70°C (pH-7) in the presence of air. The UV-Vis absorption maximum obtained is 573 nm. The crystal lattice (fcc) structure of Cu Nps was confirmed by X-ray diffraction (XRD). The novel jasmine bud shape was visualized in a transmission electron microscope (TEM). The height of single copper nanobud was 6.41 nm as measured by atomic force microscope (AFM). The average particle size 6.95 nm is obtained by XRD results. Antibacterial activity of the Cu nanobuds was evaluated by testing against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria.

scholarly journals Mechanisms of catalytic reduction of CO2 with heme and nonheme metal complexes

2018 ◽  
Vol 9 (28) ◽  
pp. 6017-6034 ◽  
Author(s):  
Shunichi Fukuzumi ◽  
Yong-Min Lee ◽  
Hyun S. Ahn ◽  
Wonwoo Nam
Keyword(s):  
Metal Complex ◽  
Metal Complexes ◽  
Critical Review ◽  
Catalytic Reduction ◽  
Electron Reduction ◽  
Reduction Of Co2 ◽  
Metal Complex Catalysts

This critical review discusses the thermal and photocatalytic mechanisms of one-, two-, four-, six- and eight-electron reduction of CO2 with metal complex catalysts.

scholarly journals Optimization of sol-immobilized bimetallic Au–Pd/TiO 2 catalysts: reduction of 4-nitrophenol to 4-aminophenol for wastewater remediation

2020 ◽  
Vol 378 (2176) ◽  
pp. 20200057
Author(s):  
Khaled Alshammari ◽  
Yubiao Niu ◽  
Richard E. Palmer ◽  
Nikolaos Dimitratos
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
Catalytic Performance ◽  
Reducing Agent ◽  
Wastewater Remediation ◽  
X Ray ◽  
Molar Ratios ◽  
Highly Active ◽  
Transmission Electron ◽  
Complementary Techniques

A sol-immobilization method is used to synthesize a series of highly active and stable Au x Pd 1− x /TiO 2 catalysts (where x  = 0, 0.13, 0.25, 0.5, 0.75, 0.87 and 1) for wastewater remediation. The catalytic performance of the materials was evaluated for the catalytic reduction of 4-nitrophenol, a model wastewater contaminant, using NaBH 4 as the reducing agent under mild reaction conditions. Reaction parameters such as substrate/metal and substrate/reducing agent molar ratios, reaction temperature and stirring rate were investigated. Structure-activity correlations were studied using a number of complementary techniques including X-ray powder diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. The sol-immobilization route provides very small Au–Pd alloyed nanoparticles, with the highest catalytic performance shown by the Au 0.5 Pd 0.5 /TiO 2 catalyst. This article is part of a discussion meeting issue ‘Science to enable the circular economy’.

Shape-Controlled Synthesis and Formation Mechanism of Cobalt Nanopowders by a PVP-Assisted Method

2010 ◽  
Vol 654-656 ◽  
pp. 1186-1189 ◽  
Author(s):  
Bing Cong Zhang ◽  
Hong Ying Yu ◽  
Dong Bai Sun
Keyword(s):  
Hydrazine Hydrate ◽  
Chemical Reduction ◽  
Reducing Agent ◽  
Soft Template ◽  
Basic Solution ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Nucleation Sites ◽  
Shape Controlled

Three different kinds of morphologies including spherical, chainlike and wirelike cobalt nanopowders, have been synthesized by chemical reduction of coblat chloride solution with hydrazine hydrate in basic solution. The products were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). It was revealed that the morphologies of the nanopowders depend on the concentration of Co2+ and the way of adding reducing agent (hydrazine hydrate). These two features affected the nucleation sites and the number of nucleuses. When the concentration of Co2+ was low, nucleuses formed in the soft template, while the reducing of the reducing agent added drop wise, a little number of nucleuses was formed. Based on that, a mechanism of formation, as a basis of gram-scale syntheses, was proposed.

Sign in / Sign up

Export Citation Format

Share Document