Aluminum Doped Titania as a Support of Copper Catalysts for SCR of Nitrogen Oxides

Aluminum doped titania samples were synthesized as supports of copper oxide catalysts for NO reduction with ammonia. Samples were prepared by the sol-gel method with various ratios of aluminum to titanium. Their thermal stability was examined by TG/DSC methods which revealed that precursors were decomposed at 450 °C. The XRD measurements showed that aluminum caused the diminishing of titania crystallites and was built into the anatase structure or formed an amorphous phase. The admixture of aluminum in titania resulted in a significant increase in specific surface area of mesoporous supports as determined by low temperature sorption of nitrogen. Results of the catalytic tests over copper/aluminum-titania samples obtained by impregnation pointed out that the addition of aluminum broadened the temperature window of high catalytic activity. The increase in Al concentration shifted the temperature of maximum activity to higher values, and at the same time lowered nitrous oxide formation as well. Better catalytic efficiency could result from high copper dispersion on the catalysts surface, as well as the synergistic interaction between Ti and Cu causing reduction in CuO species as confirmed by XPS measurements. It was shown that copper was present as Cu+ species mainly, forming Cu-O-Ti bonds on the catalysts surface.

Iron-Zinc Co-Doped Titania Nanocomposite: Photocatalytic and Photobiocidal Potential in Combination with Molecular Docking Studies

In the current research study, iron-zinc co-doped TiO2 was reported as an energy efficient material for the degradation of DIPA and inactivation of E. coli and S. aureus under visible light irradiation. In addition, molecular docking simulation was performed to provide further insight into possible targets for inhibiting bacterial development. The synthesized nanocomposites were screened and optimized for different synthesis and reaction parameters. The physicochemical properties of the synthesized nanocomposites were evaluated through different characterization techniques. The wet impregnation (WI) approach was among the most successful methods for the synthesis of Fe-Zn-TiO2 nanocomposite (NC) utilizing anatase titanium. Moreover, 66.5% (60 min reaction time) and 100% (190 min reaction time) chemical oxygen demand (COD) removal was obtained through optimized NC, i.e., 0.1Fe-0.4Zn metal composition and 300 °C calcination temperature. The energy consumption for the best NC was 457.40 KW h m−3. Moreover, 0.1Fe-0.4Zn-TiO2-300 was more efficient against S. aureus compared to E. coli with 100% reduction in 90 min of visible light irradiations. Furthermore, 0.1Fe-0.4Zn-TiO2-300 NC showed that the binding score for best docked conformation was −5.72 kcal mol−1 against β-lactamase from E. coli and −3.46 kcal mol−1 from S. aureus. The studies suggested the Fe-Zn in combination with TiO2 to be a possible inhibitor of β-lactamase that can be further tested in enzyme inhibition studies.