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 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.

scholarly journals Influence of the Active Phase (Fe, Ni, and Ni–Fe) of Mixed Oxides in CWAO of Crystal Violet

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1053 ◽  
Author(s):  
Katherine Archila ◽  
Ana María Campos ◽  
Lorena Lugo ◽  
Crispín Astolfo Celis ◽  
Sonia Moreno ◽  
...  
Keyword(s):  
Crystal Violet ◽  
Atmospheric Pressure ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Oxygen Demand ◽  
Textural Properties ◽  
Active Phase ◽  
Catalytic Wet Air Oxidation ◽  
Air Oxidation ◽  
Wet Air Oxidation

The catalytic oxidation of aqueous crystal violet (CV) solutions was investigated using Ni and Fe catalysts supported over Mg–Al oxides synthesized by the autocombustion method. The influence of temperature, loading, and selectivity were studied in the catalytic wet air oxidation (CWAO) of CV. The kind of metal had an important contribution in the redox process as significant differences were observed between Fe, Ni, and their mixtures. The catalysts with only Fe as active phase were more efficient for the oxidation of CV under normal conditions (T = 25 °C and atmospheric pressure) compared to those containing Ni, revealing the influence of the transition metal on catalytic properties. It was found that iron-containing materials displayed enhanced textural properties. The synthesis of Fe/MgAl catalysts by the autocombustion method led to solids with excellent catalytic behavior, 100% CV degradation in eight hours of reaction, 68% selectivity to CO2, and significant reduction of chemical oxygen demand (COD).

Ruthenium catalysts supported on TiO2 prepared by sol–gel way for p-hydroxybenzoic acid wet air oxidation

2008 ◽  
Vol 48 (3) ◽  
pp. 344-349 ◽  
Author(s):  
Mohamed Triki ◽  
Doan Pham Minh ◽  
Zouhaier Ksibi ◽  
Abdelhamid Ghorbel ◽  
Michèle Besson
Keyword(s):  
Sol Gel ◽  
Ruthenium Catalysts ◽  
Hydroxybenzoic Acid ◽  
Air Oxidation ◽  
Wet Air Oxidation
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