Cationic and anionic metalloporphyrins simultaneously immobilized onto raw halloysite nanoscrolls catalyze oxidation reactions

• Raw halloysite nanoscrolls were used as support to metalloporphyrins.
• Positive and negative charged metalloporphyrins were simultaneously immobilized.
• The materials were used as catalysts in alkane and alkene oxidation reactions.
• Synergistic effects between the immobilized metalloporphyrins were observed.
• Different compounds in the same support pave the way to multifunctional catalysts.

We simultaneously immobilized an anionic iron(III) porphyrin (FePor) and a cationic manganese(III) porphyrin (MnPor) onto raw halloysite nanoscrolls. The positive and negative residual charges at the edges of the halloysite nanoscrolls and the negative residual charges on the surface of this support favored FePor and MnPor immobilization. We characterized the material containing simultaneously immobilized FePor and MnPor (FeMn-Hallo) by powder X-ray diffraction, Fourier transform infrared spectroscopy, textural analysis, and UV–vis spectroscopy (solid sample); these techniques confirmed that both FePor and MnPor were present on the support. We also investigated whether FeMn-Hallo catalyzed cyclooctene epoxidation as well as cyclohexane and n-heptane oxidation. FeMn-Hallo was an effective catalyst for oxidation reaction, attesting the efficiency and versatility of both immobilized metalloporphyrins in the same support. The simultaneous immobilization of metalloporphyrins paves the way for chemists to develop multifunctional catalysts that can simultaneously promote distinct reactions.

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