scholarly journals Ultra-Fast Degradation of p-Aminophenol by a Nanostructured Iron Catalyst

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2166 ◽  
Author(s):  
Rocio Benavente ◽  
David Lopez-Tejedor ◽  
Carlos Perez-Rizquez ◽  
Jose Palomo

Full degradation of p-aminophenol in aqueous solution at room temperature by using a heterogeneous nanostructured iron hybrid catalyst in the presence of hydrogen peroxide is described. A nanostructured iron catalyst was prepared by in situ formation of iron carbonate nanorods on the protein network using an aqueous solution of an enzyme, lipase B from Candida antarctica (CAL-B). A second kind of iron nanostructured catalyst was obtained by the sunsequent treatment of the hybrid with an aqueous liquid extract of Mentha x piperita. Remarkable differences were observed using TEM imaging. When M. piperita extract was used, nanoparticles appeared instead of nanorods. Catalytic activity of these iron nanocatalysts was studied in the degradation of the environmental pollutant p-aminophenol (pAP) under different operating parameters, such as pH, presence of buffer or hydrogen peroxide concentration. Optimal conditions were pH 4 in acetate buffer 10 mM containing 1% (v/v) H2O2 for FeCO3NRs@CALB, while for FeCO3NRs@CALB-Mentha, water containing 1% (v/v) H2O2, resulted the best. A complete degradation of 100 ppm of pAP was achieved in 2 and 3 min respectively using 1 g Fe/L. This novel nanocatalyst was recycled five times maintaining full catalytic performance.

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 7 ◽  
Author(s):  
Noelia Losada-Garcia ◽  
Alba Rodriguez-Otero ◽  
Jose M. Palomo

Copper nanoparticles–enzyme biohybrid is a promising material for the remediation of contaminated waters, but its function is influenced by its effect on degradation organic pollutants. This study is the first investigation into the fast degradation of a high amount of Bisphenol A (BPA) in water at neutral pH and room temperature. Four different CuNPs biohybrids with different cu species and nanoparticle sizes were used as catalysts. The biohybrid CuNPs@CALB-3, which contained Cu2O nanoparticles of around 10 nm size, showed excellent catalytic performance removing >95% BPA content (45 ppm) in an aqueous solution in 20 min in the presence of hydrogen peroxide at pH 8 using 1.5 g/L of a catalyst. The catalyst showed excellent stability and recyclability at these conditions.


Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1015 ◽  
Author(s):  
Liangfeng Zhang ◽  
Simin Liu ◽  
Yuhua Wang ◽  
Haijun Zhang ◽  
Feng Liang

A series of gold nanoparticles (AuNPs) was prepared in situ with different cucurbit[n]urils (CB[n]s) in an alkaline aqueous solution. The nanoparticle sizes can be well controlled by CB[n]s (n = 5, 6, 7, 8) with different ring sizes. The packing densities of CB[5–8] and free surface area on AuNPs were determined. A direct relationship was found between the ring size and packing density of CB[n]s with respect to the AuNP-catalyzed reduction of 4-nitrophenol in the presence of NaBH4. The larger particle size and higher surface coverage of bigger CB[n]-capped AuNPs significantly decreased the catalytic activity. Furthermore, this work could lead to new applications that utilize AuNPs under an overlayer of CB[n]s for catalysis, sensing, and drug delivery.


2018 ◽  
Vol 20 (3) ◽  
pp. 53-59 ◽  
Author(s):  
Marlena Musik ◽  
Eugeniusz Milchert ◽  
Kornelia Malarczyk-Matusiak

Abstract The course of epoxidation of sesame oil (SO) with performic acid formed „in situ” by the reaction of 30 wt% hydrogen peroxide and formic acid in the presence of sulfuric acid(VI) as a catalyst was studied. The most advantageous of the technological independent parameters of epoxidation are as follows: temperature 80°C, H2O2/ C=C 3.5:1, HCOOH/C=C 0.8:1, amount of catalyst as H2SO4/(H2O2+HCOOH) 1 wt%, stirring speed at least 700 rpm, reaction time 6 h. The iodine number (IN), epoxy number (EN), a relative conversion to oxirane (RCO) and oxirane oxygen content (EOe) were determined every hour during the reaction. Under optimal conditions the sesame oil conversion amounted to 90.7%, the selectivity of transformation to epoxidized sesame oil was equal to 93.2%, EN = 0.34 mol/100 g, IN = 0.04 mol/100 g oil (10.2 g/100 g oil), a relative conversion to oxirane RCO = 84.6%, and oxirane oxygen content of EOe = 5.5%.


2013 ◽  
Vol 68 (10) ◽  
pp. 1138-1142 ◽  
Author(s):  
Lilian R. Graser ◽  
Sophie Jürgens ◽  
Michael E. Wilhelm ◽  
Mirza Cokoja ◽  
Wolfgang A. Herrmann ◽  
...  

Polyoxomolybdates were generated in situ by treating a carboxylic acid-functionalized ionic liquid with an aqueous solution of sodium molybdate. This reaction mixture was applied in the catalytic epoxidation of olefins using hydrogen peroxide as oxidant. The influence of acid and catalyst concentration as well as of the reaction temperature was investigated. The system showed a good performance for the epoxidation reaction and can be reused several times without a significant loss of activity. We present an easy, cheap and environmentally friendly catalytic system for the epoxidation of cis-cyclooctene.


Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2711
Author(s):  
Francesca Mangiavacchi ◽  
Letizia Crociani ◽  
Luca Sancineto ◽  
Francesca Marini ◽  
Claudio Santi

A simple, efficient, and selective oxidation under flow conditions of sulfides into their corresponding sulfoxides and sulfones is reported herein, using as a catalyst perselenic acid generated in situ by the oxidation of selenium (IV) oxide in a diluted aqueous solution of hydrogen peroxide as the final oxidant. The scope of the proposed methodology was investigated using aryl alkyl sulfides, aryl vinyl sulfides, and dialkyl sulfides as substrates, evidencing, in general, a good applicability. The scaled-up synthesis of (methylsulfonyl)benzene was also demonstrated, leading to its gram-scale preparation.


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