Catalytic Wet Air Oxidation of Oxalic Acid at Atmospheric Pressure

Catalytic wet air oxidation of oxalic acid in aqueous solution was investigated in a stirred reactor over a Pt (0.7% in wt)/Al2O3 catalyst at atmospheric pressure, in a concentration range of oxalic acid of 500-3000 ppm, and at a temperature range of 313-353 K. The conversions obtained after 5 h were 28.96 %, 45.98 % and 30.74 % for initial concentrations of 500, 1500, 3000 ppm, respectively. A rate equation of oxalic acid oxidation, in mol.h-1.g-1Pt was determined from measurements of initial rates, at different initial concentrations of oxalic acid, temperatures and catalyst mass loads. The activation energy for oxalic acid conversion was found to be 24.6 kJ mol-1.The heterogeneous catalyzed free-radical oxidation of oxalic acid was discussed.

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Degradation of Cationic Red GTL by Catalytic Wet Air Oxidation over Mo–Zn–Al–O Catalyst under Room Temperature and Atmospheric pressure

Environmental Science & Technology ◽

10.1021/es203531q ◽

2012 ◽

Vol 46 (5) ◽

pp. 2856-2863 ◽

Cited By ~ 37

Author(s):

Yin Xu ◽

Xiaoyi Li ◽

Xiang Cheng ◽

Dezhi Sun ◽

Xueye Wang

Keyword(s):

Atmospheric Pressure ◽

Room Temperature ◽

Catalytic Wet Air Oxidation ◽

Air Oxidation ◽

Wet Air Oxidation

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

Catalysts ◽

10.3390/catal10091053 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1053 ◽

Cited By ~ 1

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).

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Mechanothermal Approach for N-, S-, P-, and B-Doping of Carbon Nanotubes: Methodology and Catalytic Performance in Wet Air Oxidation

C – Journal of Carbon Research ◽

10.3390/c5020030 ◽

2019 ◽

Vol 5 (2) ◽

pp. 30 ◽

Cited By ~ 2

Author(s):

Olívia Salomé G. P. Soares ◽

Raquel P. Rocha ◽

José J. M. Órfão ◽

Manuel Fernando R. Pereira ◽

José L. Figueiredo

Keyword(s):

Carbon Nanotubes ◽

Oxalic Acid ◽

Sodium Thiosulfate ◽

Chemical Properties ◽

Rare Earth Oxide ◽

Acid Oxidation ◽

Dihydrogen Phosphate ◽

Air Oxidation ◽

Wet Air Oxidation ◽

Sodium Dihydrogen Phosphate

The texture and the surface chemistry of carbon nanotubes (CNTs) were modified using a solvent-free methodology involving a ball-milling mechanical treatment and thermal treatment under nitrogen in the presence of adequate precursors (melamine, sodium thiosulfate, sodium dihydrogen phosphate, and boric acid) of different heteroatoms (N, S, P, and B, respectively). The incorporation of these heteroatoms promotes significant changes in the pristine textural and chemical properties. This easy post-doping method allows the introduction of large concentrations of heteroatoms. Their effect on the catalytic activity of the materials was evaluated in the oxidation of oxalic acid by catalytic wet air oxidation (CWAO), as an alternative to the noble metal and rare earth oxide catalysts traditionally used in this process. Improved catalytic activities were obtained using the N-, P-, and B-doped CNTs in oxalic acid oxidation, while the S-doped CNT sample underperformed in comparison to the pristine material.

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