• BHASKAR DEVU MUKRI

      Articles written in Journal of Chemical Sciences

    • Ce0.98Pd0.02O$_{2-\delta}$: Recyclable, ligand free palladium(II) catalyst for Heck reaction

      S R Sanjaykumar Bhaskar Devu Mukri Satish Patil Giridhar Madras M S Hegdea

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      Palladium substituted in cerium dioxide in the form of a solid solution, Ce0.98 Pd0.02 O1.98 is a new heterogeneous catalyst which exhibits high activity and 100% trans-selectivity for the Heck reactions of aryl bromides including heteroaryls with olefins. The catalytic reactions work without any ligand. Nanocrystalline Ce0.98 Pd0.02 O1.98 is prepared by solution combustion method and Pd is in +2 state. The catalyst can be separated, recovered and reused without significant loss in activity.

    • High rates of catalytic hydrogen combustion with air over Ti ₀. ₉₇Pd ₀. ₀3O ₂ δ coated cordierite monolith

      BHASKAR DEVU MUKRI M S HEGDE

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      Ti ₀. ₉₇Pd ₀. ₀3O ₂ δ was coated on γ -Al ₂O ₃-coated honeycomb structured cordierite monolith (AHCM) by solution combustion method using dip-dry-heat process. This is a modified conventional method to coat the catalysts on honeycomb structured cordierite monolith (HCM). Formation of Ti ₀. ₉₇Pd ₀. ₀3O ₂ δ on AHCMwas confirmed by XRD. The XPS spectra of Pd(3d) core level confirmed Pd ion in Ti ₀. ₉₇Pd ₀. ₀3O ₂ δ is in the form of +2 state.The surface morphology of coated catalystwas unchanged by long time exposure to hydrogencombustion reaction; i.e., H ₂ +O ₂ recombination reaction which indicated the stability of coating on monolith. Ti ₀. ₉₇Pd ₀. ₀3O ₂ δ showed high rates of H ₂ + O ₂ recombination compared to 2 atom% Pd(metal)/γ -Al ₂O ₃, Ce ₀. ₉₈Pd ₀. ₀ ₂O₂ δ ,Ce ₀. ₉₈Pt ₀. ₀ ₂O₂ δ Ce ₀. ₇₃Zr ₀. ₂₅Pd ₀. ₀ ₂O₂ δ, Ti ₀. ₉₉Pd ₀. ₀ ₁O₂ δ and Ti ₀. ₉₈Pd ₀. ₀ ₂O₂ δ. The activation energy of H ₂ + O ₂ recombination reaction over Ti ₀. ₉₇Pd ₀. ₀3O ₂ δ is 7.8 kcal/mol. The rates of reaction over Ti ₀. ₉₇Pd ₀. ₀3O ₂ δ at 60◦C are in the range between 10 and 20 μmol/g/s. The rate of reaction over Ti ₀. ₉₇Pd ₀. ₀3O ₂ δ increased with increase in the concentration of H ₂. For 50 mL of H ₂, it showed rates of the reaction around 36.45 μmol/g/s at room temperature and 230 μmol/g/s at 60◦C. It was found that the rate of reaction due was lower due to hindering effect by adsorption of other gas molecules on the catalytic site.Finally, we propose a mechanism of hydrogen and oxygen recombination reaction over Ti ₀. ₉₇Pd ₀. ₀3O ₂ δ.

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