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oai:gredos.usal.es:10366/1509112026-01-15T10:39:56Zcom_10366_4164com_10366_4055com_10366_3946com_10366_3823col_10366_4165

Faria, Emerson Henrique de Ricci, Gustavo P. Marçal, Liziane Nassar, Eduardo J. Vicente Rodríguez, Miguel Ángel Trujillano Hernández, Raquel Gil, Antonio Korili, S.A. Ciuffi, Katia J. Calefi, Paulo S. 2022-10-27T11:33:24Z 2022-10-27T11:33:24Z 2012 Emerson H. de Faria, Gustavo P. Ricci, Liziane Marçal, Eduardo J. Nassar, Miguel A. Vicente, Raquel Trujillano, Antonio Gil, Sophia A. Korili, Katia J. Ciuffi, Paulo S. Calefi, Green and selective oxidation reactions catalyzed by kaolinite covalently grafted with Fe(III) pyridine-carboxylate complexes, Catalysis Today, Volume 187, Issue 1, 2012, Pages 135-149, ISSN 0920-5861, https://doi.org/10.1016/j.cattod.2011.11.029. (https://www.sciencedirect.com/science/article/pii/S0920586111008054) 0920-5861 http://hdl.handle.net/10366/150911 10.1016/j.cattod.2011.11.029 The immobilization of Fe(III) picolinate and Fe(III) dipicolinate complexes on kaolinite furnished heterogeneous catalysts, whose catalytic activity was evaluated. The precursor materials were kaolinite grafted with picolinic (Ka-pa) and dipicolinic (Ka-dpa) acids obtained by melting of the pyridine carboxylic acids. To obtain the catalysts Fe(Ka-pa)-n and Fe(Ka-dpa)-n (n = 1, 2, or 3 is the ligand/Fe ratio), the precursors were suspended in Fe3+ solutions with cation/ligand ratios of 1:1, 1:2, or 1:3. The resulting materials were characterized by thermal analyses (simultaneous TG/DTA), X-ray diffraction, UV/vis and infrared spectroscopies, and transmission electron microscopy. The grafted complexes were employed as heterogeneous catalysts in the epoxidation of cis-cyclooctene to cis-cyclooctenoxide and in the oxidation of cyclohexane to cyclohexanol and cyclohexanone at ambient temperature and pressure. Hydrogen peroxide was used as oxygen donor at a catalyst/oxidant/substrate molar ratio of 1:300:100. Fe(Ka-pa)-n catalysts were very efficient for cis-cyclooctene epoxidation (38% conversion). For cyclohexane oxidation, Fe(Ka-dpa)-n was 100% selective for cyclohexanone formation, with substrate conversion of 14%. This last series of catalysts was also very effective in the Baeyer–Villiger reaction, with 60% substrate conversion and 100% selectivity for ξ-caprolactone. After reuse (5 times), the catalysts still led to high substrate conversion. eng http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Attribution-NonCommercial-NoDerivatives 4.0 Internacional Kaolinite Heterogeneous catalysis Fe(III)–picolinates and dipicolinates Oxidation reactions Baeyer–Villiger Green and selective oxidation reactions catalyzed by kaolinite covalently grafted with Fe(III) pyridine-carboxylate complexes info:eu-repo/semantics/article