| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 39041 | Applied Catalysis A: General | 2015 | 11 Pages |
•Cu on γ-Al2O3 catalysts were prepared and characterized.•Various bases were added to optimize and improve the catalytic performances of catalysts.•The catalytic oxidation of the methylene blue was evaluated.•Full kinetic data was obtained.•The kinetic data shows typical Langmuir–Hinshelwood kinetics.
The kinetics of the catalytic oxidation of methylene blue, with hydrogen peroxide was studied under mild conditions. Several copper catalysts were evaluated, with Cu/Li2O/γ-Al2O3 being the most active catalyst. Atomic absorption spectroscopy (AAS), X-ray diffraction spectroscopy (XRD), ligand based chemisorption (LBC), physisorption (BET), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) were used for the characterization of the catalysts, while the oxidative degradations of methylene blue were followed by ultraviolet-visible spectroscopy (UV–vis). Different intermediate species were detected by gas chromatography–mass spectrometry (GC–MS), and the degradation pathway was proposed. The kinetic data obtained could be modeled to the Langmuir–Hinshelwood model; that is both reactants are adsorbed onto the surface of the nanoparticles. The apparent reaction rate could therefore be related to the surface S of the nanoparticles, to the constant k, related to the rate determining steps, and to the adsorption constant KMB and KH2O2 of methylene blue and hydrogen peroxide, respectively.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (161 K)Download as PowerPoint slide
