scholarly journals Fabrication of Core-Shell Structural SiO2@H3[PM12O40] Material and Its Catalytic Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Xin Yang ◽  
Junhai Wang ◽  
Qi Zhang ◽  
Xu Wang ◽  
Linlin Xu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Heterogeneous Catalysts ◽  
Sol Gel ◽  
Operating Conditions ◽  
Core Shell ◽  
Catalytic Wet Air Oxidation ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Heterogeneous Catalytic ◽  
Room Condition

Through a natural tree grain template and sol-gel technology, the heterogeneous catalytic materials based on polyoxometalate compounds H3[PM12O40] encapsulating SiO2: SiO2@H3[PM12O40] (SiO2@PM12, M = W, Mo) with core-shell structure had been prepared. The structure and morphology of the core-shell microspheres were characterized by the XRD, IR spectroscopy, UV-Vis absorbance, and SEM. These microsphere materials can be used as heterogeneous catalysts with high activity and stability for catalytic wet air oxidation of pollutant dyes safranine T (ST) at room condition. The results show that the catalysts have excellent catalytic activity in treatment of wastewater containing 10 mg/L ST, and 94% of color can be removed within 60 min. Under different cycling runs, it is shown that the catalysts are stable under such operating conditions and the leaching tests show negligible leaching effect owing to the lesser dissolution.

Catalysts for Wet Air Oxidation Based on Ce-Zr-Pr-O Mixed Oxides Prepared by Soft Chemistry

2006 ◽  
Vol 45 ◽  
pp. 2089-2095
Author(s):  
Jana Mikulová ◽  
Sylvie Rossignol ◽  
Jacques Barbier Jr. ◽  
Charles Kappenstein ◽  
Daniel Duprez
Keyword(s):  
Aqueous Solution ◽  
Mixed Oxides ◽  
Platinum Catalyst ◽  
Sol Gel ◽  
Ruthenium Catalysts ◽  
Catalytic Wet Air Oxidation ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Soft Chemistry ◽  
Pure Ceria

Sol-gel Zr0.1Ce0.9O2 and Zr0.1(Ce0.75Pr0.25)O2 mixed oxides and coprecipitated pure ceria CeO2 displaying the fluorine type structure have been used as platinum or ruthenium catalysts’ supports for catalytic wet air oxidation (CWAO) of aqueous solution of acetic acid (78 mmol.L-1). These catalysts were prepared by conventional impregnation (5 wt-%) from platinum and ruthenium precursor salts or by exchange (~2 wt-%) in the case of ruthenium. A screening of catalysts in CWAO at 200°C under 2 MPa was performed and reveals that the best platinum catalyst is supported on pure ceria displaying large surface. For ruthenium catalysts, the highest conversion after 3 hours of reaction has been reached by the Ru/Zr-Ce-O system.

scholarly journals Single-atom nickel confined nanotube superstructure as support for catalytic wet air oxidation of acetic acid

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Chengyu Jin ◽  
Lei Ma ◽  
Wenjing Sun ◽  
Peiwei Han ◽  
Xiangdong Tan ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Catalytic Activity ◽  
Noble Metal ◽  
Intrinsic Property ◽  
Single Atom ◽  
General Strategy ◽  
Catalytic Wet Air Oxidation ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Ru Nanoparticles

AbstractSingle-atom confined materials (SACMs) have been widely researched as catalysts in many fields within recent years. However, this class of materials may not only serve as a catalyst but also as a support material for certain reactions. Here we propose a general strategy to use SACMs as supports for tuning loaded noble metal (e.g., Ru) nanoparticles with enhanced catalytic activity. As a proof of concept, a nickel single-atom confined nitrogen-doped carbon nanotube (NCNT) superstructure is prepared as a support to load noble metal Ru for catalytic wet air oxidation of acetic acid. Improved catalytic activity with a mineralization rate of ~97.5% is achieved. Further, adsorption configurations based on DFT calculations also confirm our deduction that the introduction of single-atom Ni changes the intrinsic property of NCNTs and affects the loaded active Ru nanoparticles.

Catalytic wet air oxidation of dye pollutants by polyoxomolybdate nanotubes under room condition

2009 ◽  
Vol 86 (3-4) ◽  
pp. 182-189 ◽  
Author(s):  
Yang Zhang ◽  
Dongliu Li ◽  
Yang Chen ◽  
Xiaohong Wang ◽  
Shengtian Wang
Keyword(s):  
Catalytic Wet Air Oxidation ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Dye Pollutants ◽  
Room Condition

Electro-assisted catalytic wet air oxidation of organic pollutants on a MnO@C/GF anode under room condition

2019 ◽  
Vol 256 ◽  
pp. 117822 ◽  
Author(s):  
Lin-Feng Zhai ◽  
Ming-Feng Duan ◽  
Meng-Xia Qiao ◽  
Min Sun ◽  
Shaobin Wang
Keyword(s):  
Organic Pollutants ◽  
Catalytic Wet Air Oxidation ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Room Condition

Kinetics Study on Heterogeneous Catalytic Wet Air Oxidation of Phenol using Copper/Activated Carbon Catalyst

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Qiang Wu ◽  
Xijun Hu ◽  
Po Lock Yue
Keyword(s):  
Mass Transfer ◽  
Activated Carbon ◽  
Molecular Form ◽  
Reaction System ◽  
Mathematic Model ◽  
Catalytic Wet Air Oxidation ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Mass Transfer Effect ◽  
Heterogeneous Catalytic

Heterogeneous kinetics of catalytic wet air oxidation (CWAO) of phenol was studied using copper supported on activated carbon as the catalyst and oxygen as the oxidant. Both mass transfer effect and deactivation of catalyst can affect the kinetics measurement. To eliminate the mass transfer barriers, the study was conducted in a stirred tank batch reactor using catalysts of very small particle size. In order to prevent the catalyst deactivation caused by copper leaching from the support, saturated pH buffer solution was added into the reaction system and the initial phenol and catalyst concentrations were reduced. A mathematic model was proposed following the Langmuir-Hinshelwood mechanism to simulate the reaction kinetics. It is believed through simulation that the dissolved oxygen is adsorbed by the catalyst in molecular form which subsequently starts to degrade phenol on the catalyst surface. Both reaction rate constant and activation energy were determined for a temperature range of 140 - 160 oC and an oxygen partial pressure range of 0.4 - 1.6 MPa. The proposed mechanism and kinetic model were found to be in good agreement with experimental results.

Reaction mechanisms and kinetics of chemical pretreatment of bioresistant organic molecules by wet air oxidation

1997 ◽  
Vol 35 (4) ◽  
pp. 119-127 ◽  
Author(s):  
D. Mantzavinos ◽  
R. Hellenbrand ◽  
A. G. Livingston ◽  
I. S. Metcalfe
Keyword(s):  
Organic Pollutants ◽  
Reaction Mechanisms ◽  
Noble Metals ◽  
Heterogeneous Catalysts ◽  
Operating Conditions ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Total Oxidation ◽  
Analytical Technique ◽  
The Impact

The partial wet air oxidation of aqueous solutions of p-coumaric acid and polyethylene glycol, two model organic pollutants typically found in wastewaters of agricultural origin and polymer-manufacturing respectively, has been investigated at temperatures from 373 K to 513 K and oxygen partial pressures from 0.2 MPa to 3 MPa. Reaction intermediates have been identified and their concentration profiles have been determined using liquid chromatography as the main analytical technique, and reaction mechanisms and pathways have been postulated. The impact of various heterogeneous catalysts, such as metal oxides and noble metals, on the kinetics and mechanisms of the reaction has also been studied. Conversion of these model compounds through various oxidation intermediates to end-products, such as carboxylic acids, could be easily achieved even under mild operating conditions, while further total oxidation proved to be difficult even under more severe conditions. Catalysts were found to be, in general, capable of increasing the rates of both partial and total uncatalysed oxidation. The stability of some of the catalysts used has also been studied with respect to metal leaching and deactivation. The implications for complete removal of bioresistant organic pollutants by partial wet oxidation followed by a biological treatment step are also discussed.

Catalytic Wet Air Oxidation of Sewage Sludge: A Review

2020 ◽  
Vol 7 (3) ◽  
pp. 199-211
Author(s):  
De-bin Li ◽  
Duo Wang ◽  
Zi-sheng Jiang
Keyword(s):  
Sewage Sludge ◽  
Noble Metal ◽  
Heterogeneous Catalysts ◽  
Metal Catalysts ◽  
Catalytic Wet Air Oxidation ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Sludge Treatment ◽  
Noble Metal Catalysts ◽  
Sewage Sludge Treatment

Wet air oxidation (WAO) is an attractive technique for sewage sludge treatment. The WAO process and the factors influencing the process are examined in detail, together with the advantages and disadvantages. Catalytic wet air oxidation (CWAO) is emphasized because it can lower operational conditions, and the commonly-used and new homogeneous and heterogeneous catalysts are introduced. Homogeneous catalysts tend to be more appropriate for the CWAO treatment of sewage sludge, and Cu-based homogeneous catalysts such as CuSO4 are the most popular for industrial applications. Heterogeneous catalysts include non-noble metal catalysts, noble metal catalysts, metal-organic frameworks (MOFs) catalysts, and non-metal catalysts. Non-noble metal catalysts typically contain hetero-elements as in Mo-based, Ce-based, Cu-based, Fe-based catalysts, multi-metal supported catalysts, and polyoxometalates catalysts. In general, Mo-based catalysts and Ce-based catalysts have higher activities than other metal-based catalysts. The commonly-used noble metal elements are based on Ru, Pt, Pd, Rh, and Ir. The MOF catalysts tend to have high catalytic activity, and the non-metallic carbon catalysts may be used in environments that would otherwise be toxic to traditional metal catalysts. To conclude, a summary of the challenges and prospects of WAO technology in sewage sludge treatment is given.

Synthesis of ZnMoO4/Na2Mo4O13/α-MoO3 Hybrid Catalyst for the Catalytic Wet Air Oxidation of Dye Under Room Condition

2014 ◽  
Vol 6 (10) ◽  
pp. 2159-2164 ◽  
Author(s):  
Zhang Zhang ◽  
Ruoyan Yang ◽  
Ahmad Umar ◽  
Yanshan Gao ◽  
Junya Wang ◽  
...  
Keyword(s):  
Catalytic Wet Air Oxidation ◽  
Hybrid Catalyst ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Room Condition
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