CO2 Conversion to Methanol over Novel Carbon Nanofiber-Based Cu/ZrO2 Catalysts—A Kinetics Study

Ongoing industrialization has deteriorated the global environment. Global warming is a human-induced issue affecting the environment. The alarming increase in CO2 emissions is among the major contributors to global warming. The conversion of CO2 to methanol is an economically viable and environmentally friendly solution to mitigate its concentration. Here, hydrogenation of CO2 was studied over carbon nanofiber-based Cu/ZrO2 catalysts. Kinetics investigations were carried out for the reaction. Overall, kinetics data indicated that CO2 conversion follows a pseudo-first-order reaction. The kinetics studies were further modeled by using an artificial neural network, which supported the experimental kinetics study.

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Reduction Kinetics and Electrochemistry Property of Ascorbic Acid

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.233-235.1752 ◽

2011 ◽

Vol 233-235 ◽

pp. 1752-1755

Author(s):

Yan Hong Zhao ◽

Xiang Li ◽

Qiang Qiang Du ◽

Li Chun Hou ◽

Xiao Jing Wang

Keyword(s):

Ascorbic Acid ◽

Order Reaction ◽

Reduction Kinetics ◽

Carbon Electrode ◽

Kinetics Study ◽

Pseudo First Order Reaction ◽

Glass Carbon Electrode ◽

First Order ◽

Glass Carbon ◽

Pseudo First Order

The article reported the reduction of methylene blue (abbreviated as MB) by ascorbic acid (abbreviated as AA) in aqueous solution. The kinetics study revealed that the reduction proceeds of MB by AA was the pseudo first order reaction. In addition, the electrochemical property of reductant AA was investigated by cyclic voltammetry (CV). The CV result indicated that the electrochemical oxide of AA was diffusion controlling at glass carbon electrode (GCE).

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Optimization and Kinetics of Bioadsorption of Aqueous Potassium Permanganate in Charred Cacao Shells

KIMIKA ◽

10.26534/kimika.v31i2.80-90 ◽

2020 ◽

Vol 31 (2) ◽

pp. 80-90

Author(s):

Cyrus Ariel D.R. Fornoles ◽

Naela V. Delmo ◽

Alvin Manuel M. Traje ◽

Sheryl Lozel B. Arreola ◽

Amelia B. Hizon-Fradejas ◽

...

Keyword(s):

Potassium Permanganate ◽

Removal Efficiency ◽

Order Reaction ◽

Pseudo First Order Reaction ◽

Adsorption Parameters ◽

First Order ◽

Kinetics Studies ◽

Adsorption Data ◽

Other Substances ◽

Kinetics Of

In this study, charred cacao shells were tested for their capability as bioadsorbent for aqueous potassium permanganate. Optimization of adsorption parameters showed that the best amount of adsorbent is 0.5% w of cacao biochar/v of 0.005 N aqueous KMnO4 with a removal efficiency of 98.79%, and the optimum particle size is 212 mm, with a corresponding removal efficiency of 99.76%. Kinetics studies showed that the adsorption fits a pseudo-first order reaction with R2 = 0.9833. Lastly, the adsorption data fits the Elovich isotherm with R2 = 0.9712, which strongly suggests a multi-layer chemisorption on a heterogenous surface. Conclusively, the charred cacao shells were found to be effective as an adsorbent of aqueous potassium permanganate. Furthermore, the resulting product of adsorption can be used to study adsorption of other substances due to its multi-layer nature.

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Multifactorial optimization of the decolorisation parameters of wastewaters resulting from dyeing flowers

Water Science & Technology ◽

10.2166/wst.2009.114 ◽

2009 ◽

Vol 59 (7) ◽

pp. 1361-1369 ◽

Cited By ~ 3

Author(s):

Edison Gil Pavas ◽

Miguel Ángel Gómez-García

Keyword(s):

Hydrogen Peroxide ◽

Organic Matter ◽

Experimental Design ◽

Order Reaction ◽

Pseudo First Order Reaction ◽

First Order ◽

Effluent Standards ◽

Degradation Of Dyes ◽

Pseudo First Order ◽

Dyes Mixture

This work deals with the treatment of the wastewaters resulting from the process of dyeing flowers. In some local cases for growing flowers near to Medellín (Colombia), wastewater color was found to be one of the main problems in meeting local effluent standards. Wastewaters were treated by photodegradation process (which includes photocatalysis) to achieve the degradation of dyes mixture and organic matter in the wastewater. A multifactorial experimental design was proposed, including as experimental factors the following variables: pH, and the concentration of both catalyst (TiO2) and hydrogen peroxide (H2O2). According to the obtained results, at the optimized variables values, it is possible to reach a 99% reduction of dyes, a 76.9% of mineralization (TOC) and a final biodegradability of 0.834. Kinetic analysis allows proposing a pseudo first order reaction for the reduction, the mineralization, and the biodegradation processes.

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Reuse of Newspaper As An Adsorbent For Cu (II) Removal By Citric Acid Modification

MATEC Web of Conferences ◽

10.1051/matecconf/201815602012 ◽

2018 ◽

Vol 156 ◽

pp. 02012 ◽

Cited By ~ 1

Author(s):

Mardiah ◽

Rif’an Fathoni ◽

Pratiwi Pudyaningtyas ◽

Hamdania Gamu ◽

Rinaldy

Keyword(s):

Citric Acid ◽

Adsorption Process ◽

Kinetic Studies ◽

Order Reaction ◽

Acid Modification ◽

Pseudo First Order Reaction ◽

First Order ◽

Pseudo Second Order ◽

Heavy Metal Adsorbent ◽

The Impact

High Consumption of paper, bring the impact of the waste paper itself. And the utilization of the paper is limited to recycled products and crafts, whereas paper such as newspaper still contains cellulose that can be potential to be used as a heavy metal adsorbent. In this study, newspaper was dissolved in sodium bicarbonate to reduce various impurities and then was reacted with citric acid (CA). The modified adsorbent was characterized by FTIR and was tested for adsorb Cu(II) in artificial solution. After adsorption process, the solution was filtered and analysed using Atomic Absorption Spectrophotometer (AAS). The adsorption experimental data was fitted to Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich for equilibrium model and was fitted to pseudo first order reaction and pseudo second order reaction for kinetic studies. The result showed that CA-modification newspaper able to remove heavy metals Cu(II) in solution.

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Photocatalytic degradation of sulfamethazine in aqueous solution using ZnO with different morphologies

Royal Society Open Science ◽

10.1098/rsos.171457 ◽

2018 ◽

Vol 5 (4) ◽

pp. 171457 ◽

Cited By ~ 12

Author(s):

Zhigang Yi ◽

Juan Wang ◽

Tao Jiang ◽

Qiong Tang ◽

Ying Cheng

Keyword(s):

Aqueous Solution ◽

Photocatalytic Degradation ◽

Reaction System ◽

Degradation Pathway ◽

Order Reaction ◽

Pseudo First Order Reaction ◽

First Order ◽

Different Shapes ◽

Pseudo First Order ◽

Release Ratio

In this study, photocatalytic experiments of 20 mg l −1 sulfamethazine (SMN) in aqueous solution containing ZnO with different morphologies, tetra-needle-like ZnO (T-ZnO), flower-like ZnO (F-ZnO) and nanoparticles ZnO (P-ZnO), were performed. The results indicated that photocatalytic degradation of SMN was effective and followed the pseudo-first-order reaction, but the degree of SMN mineralization showed obvious differences using ZnO with different shapes. After 12 h irradiation, 86%, 71% and 50% of the initial total organic carbon was eliminated in SMN suspension containing T-ZnO, F-ZnO and P-ZnO, respectively. The release ratio of sulfur was close to 100% in the presence of T-ZnO, but reached to 86% and 67% in the presence of F-ZnO and P-ZnO, respectively. The release ratio of nitrogen was about 76%, 63% and 40% using T-ZnO, F-ZnO and P-ZnO as photocatalyst, respectively. The morphology of ZnO played an important role in determining its catalytic activity. Seven intermediates were observed and identified in the UV/T-ZnO reaction system by LC-MS/MS analysis, and a possible degradation pathway was proposed.

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On the Chemical Reactivity of the Phytochrome Chromophore in the Pr and Pfr Form

Zeitschrift für Naturforschung C ◽

10.1515/znc-1985-3-413 ◽

1985 ◽

Vol 40 (3-4) ◽

pp. 215-218 ◽

Cited By ~ 27

Author(s):

Fritz Thümmler ◽

Peter Eilfeld ◽

Wolfhart Rüdiger ◽

Doo-Khil Moon ◽

Pill-Soon Song

Keyword(s):

Reaction Kinetics ◽

Rate Constants ◽

Chemical Reactivity ◽

Order Reaction ◽

First Order Reaction ◽

Limiting Factor ◽

Pseudo First Order Reaction ◽

First Order ◽

Pseudo First Order ◽

The Difference

The reactivity of the phytochrome chromophore and related tetrapyrroles towards ozone and tetranitromethane was investigated. Both oxidizing reagents cause bleaching of the main absorption band of the pigment. The rate constants for this bleaching were determined under conditions of pseudo first order reaction kinetics. The rate constants for the reaction with ozone are similar for native phytochrome and for freely accessible tetrapyrroles (biliverdin, small chromopeptides from phytochrome) indicating that accessibility is not the limiting factor for the reaction with ozone. Under a variety of conditions, the Pfr chromophore reacts by about 10% faster than the Pr chromophore. This may reflect the true difference in reactivity. The rate constants for the reaction with tetranitromethane are much larger for biliverdin, bilirubin and small chromopeptides from phytochrome than for native phytochrome. The limiting factor for this reaction in native phytochrome therefore is the accessibility of the chromophore by the reagent. Previous conclusions on the difference in exposure of the tetrapyrrole chromophore in Pr and Pfr are confirmed.

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FIBRINOPEPTIDE B RELEASE FROM NORMAL FIBRINOGEN AND FIBRINOGEN LONDON I IN THE PRESENCE OF INHIBITORS OF FIBRIN POLYMERIZATION

10.1055/s-0038-1643341 ◽

1987 ◽

Author(s):

W Ruf ◽

A Bender ◽

K T Preissner ◽

D A Lane ◽

G Müller-Berghaus

Keyword(s):

Initial Phase ◽

Slow Rate ◽

Order Reaction ◽

Pseudo First Order Reaction ◽

Reaction Conditions ◽

Fibrin Polymerization ◽

First Order ◽

Molar Excess ◽

Pseudo First Order ◽

Fibrinogen Molecule

The fibrinopeptides A and B (FPA and FPB) are cleaved from the fibrinogen molecule with different rates. In the initial phase of the thrombin-fibrinogen reaction, FPB is released with a slow rate, which is enhanced upon polymerization of desA-fi-brin monomers. The aim of the present study was to further characterize the mechanism leading to the enhanced rate of FPB release during polymerization. For this purpose, the release of FPB from normal fibrinogen and from fibrinogen London I, which exhibits a polymerization defect located in the D-domain, was studied in the presence and absence of the fibrinolytic fragment D1 (D1) and of the synthetic tetrapeptide Gly-Pro-Arg-Pro (GPRP). Steady state parameters for fibrinopeptide release were determined under pseudo-first order reaction conditions. In the initial phase of the thrombin-fibrinogen reaction, the release of FPA was unchanged in the presence of D1. Furthermore, the release of FPA from fibrinogen London I did not reveal any difference in comparison to normal fibrinogen. GPRP prevented not only fibrin polymerization, but also the enhanced rate of FPB release. On the contrary, the rate of FPB release in the presence of a 16- and 32-fold molar excess of over fibrinogen did not differ from a reaction mixture with no added D1. Si-miliar to the inhibited rate of FPB release in the presence of GPRP, the release of FPB from fibrinogen London I occurred with a slow rate, which was not enhanced by the addition of a 16-fold molar excess of D1. Since the release neither from normal fibrinogen nor from ribrinogen London I was affected by D1, it was concluded that the D-E contact formed by D1 with an E-domain of a desA-fibrin molecule does not enhance the release of FPB. While GPRP keeps fibrin in monomeric form by inhibiting the polymerization sites in the D-domains, D1 does not prevent the formation of fibrin oligomers. Therefore, acceleration of FPB release is caused by a conformational change, which is induced by binding of reciprocal polymerization sites to an E-as well as a D-domain of the same desA-fibrin molecule.

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Effect of Cyclodextrins on Photodegradation of 4,4-Bis(4-Hydroxyphenyl)Pentanoic Acid under UV Irradiation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.665.455 ◽

2014 ◽

Vol 665 ◽

pp. 455-458

Author(s):

Li Guo ◽

Jin Huang ◽

Jun Wu ◽

Lei Lei Luo

Keyword(s):

Aqueous Solutions ◽

Fluorescence Spectra ◽

High Efficiency ◽

Uv Light ◽

Order Reaction ◽

Pentanoic Acid ◽

Pseudo First Order Reaction ◽

First Order ◽

Inclusion Interaction ◽

Pseudo First Order

The photodegradation of 4,4-bis (4-hydroxyphenyl) pentanoic acid (DPA) with two cyclodextrins (α-CD and β-CD ) in aqueous solutions induced by UV-light was studied in this paper by means of fluorescence spectra and high efficiency liquid chromatography. The result suggested that DPA with α-CD or β-CD formed inclusion compound in aqueous solutions. The photodegradation of DPA with two cyclodextrins or without cyclodextrin was pseudo-first order reaction. The photodegradation of DPA was accelerated by the addition of β-CD in aqueous solutions, but the that of DPA was inhibited in case of adding α-CD. These differences were due to the differences in inclusion interaction of DPA with α-CD or β-CD.

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Enhancement of decomposition of 2-chlorophenol with ultrasound/H2O2 process

Water Science & Technology ◽

10.2166/wst.1996.0173 ◽

1996 ◽

Vol 34 (9) ◽

pp. 41-48 ◽

Cited By ~ 17

Author(s):

Jih-Gaw Lin ◽

Cheng-Nan Chang ◽

Jer-Ren Wu ◽

Ying-Shih Ma

Keyword(s):

Ionic Strength ◽

Reaction Rate ◽

Order Reaction ◽

Pseudo First Order Reaction ◽

Initial Concentration ◽

First Order ◽

Toc Removal ◽

Cp Decomposition ◽

Effects Of Ph ◽

Pseudo First Order

We investigated the effects of pH, ionic strength, catalyst, and initial concentration on both decomposition of 2-chlorophenol (2-cp) and removal of total organic carbon (TOC) in aqueous solution with ultrasonic amplitude 120 μm and H2O2 (200 mg/l). When the initial concentrations of 2-cp was 100 mg/l and the pH was controlled at 3, the rate of 2-cp decomposition was enhanced up to 6.6-fold and TOC removal up to 9.8-fold over pH controlled at 11. At pH 3, the efficiency of decomposition of 2-cp was 99% but the removal of TOC was only 63%; a similar situation applied at pH 7 and 11. Hence intermediate compounds were produced and 2-cp was not completely mineralized. When the concentration of ionic strength was increased from 0.001 to 0.1 M, the rate of 2-cp decomposition was enhanced only 0.3-fold, whereas the TOC removal was not enhanced. In comparison of the effects of pH and ionic strength, pH had greater influence on both 2-cp decomposition and TOC removal than ionic strength. The effect of a catalyst (FeSO4) on decomposition of 2-cp was insignificant comparing with direct addition of H2O2. The reaction rate at a smaller initial concentration of 2-cp (10 mg/l) was more rapid than at a greater one (100 mg/l). The rate of 2-cp decomposition and TOC removal appeared to follow pseudo-first-order reaction kinetics.

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