Immobilization of metalloporphyrins on CeO₂@SiO₂ with a core-shell structure prepared via microemulsion method for catalytic oxidation of ethylbenzene

Abstract

CeO₂@SiO₂ core-shell nanoparticles were prepared by microemulsion method, and metalloporphyrins were immobilized on the CeO₂@SiO₂ core-shell nanoparticles surface via amide bond. The supported metalloporphyrin catalysts were characterized by N₂ adsorption-desorption isotherm (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet and visible spectroscopy (UV-Vis), and Fourier transform infrared spectroscopy (FT-IR). The results show that the morphology of CeO₂@SiO₂ nanoparticles is core-shell microspheres with about 30 nm in diameter, and metalloporphyrins are immobilized on the CeO₂@SiO₂ core-shell nanoparticles via amide bond. Especially, the core-shell structure contains multi CeO₂ core and thin SiO₂ shell, which may benefit the synergistic effect between the CeO₂ core and the porphyrin anchored on the very thin SiO₂ shell. As a result, this supported metalloporphyrin catalysts present comparably high catalytic activity and stability for oxidation of ethylbenzene with molecular oxygen, namely, ethylbenzene conversion remains around 12% with identical selectivity of about 80% for acetophenone even after six-times reuse of the catalyst.

Keywords

CeO₂@SiO₂ / core-shell structure / metalloporphyrin / ethylbenzene oxidation

References

[1] RochatS, MinardiC, HerrmannA H. Controlled release of perfumery aldehydes and ketones by norrish type-II photofragmentation of α-keto esters in undegassed solution [J]. Chim Acta, 2000, 83: 1645-1671

[2] CainelliG, CardilloGChromium oxidations in organic chemistry [M], 1984118-216

[3] RahimanA K, SreedaranS, BharathiK S, NarayananV. Metalloporphyrins encapsulated mesoporous molecular sieves as efficient heterogeneous catalysts for oxidation of cyclohexene with iodosylbenzene [J]. Porous Mater, 2010, 17: 711-718

[4] SuslickK S, BhyrappaP, ChouJ H, KosalM E, NakagakiS, SmithenryD W, WilsonS R. Microporous porphyrin solids [J]. Acc Chem Res, 2005, 38: 283-291

[5] LeadbeaterN E, MarcoM. Preparation of polymer-supported ligands and metal complexes for use in catalysis [J]. Chem Rev, 2002, 102: 3217-3274

[6] ShenD, JiL, LiuZ, ShengW, GuoC. Ethylbenzene oxidation over hybrid metalloporphyrin@silica nanocomposite microspheres [J]. J Mole Catal A: Chem, 2013, 379: 15-20

[7] GUO X, SHEN D, LI Y, TIAN M, LIU Q, GUO C, LIU Z. Immobilization of metalloporphyrin on organosilicon microsphere mixed with ceria as a new catalyst for oxidation of cyclohexane [J]. J Mol Catal A: Chem, 201, 351: 174–178.

[8] SonoM, RoachM P, CoulterE D, DawsonJ H. Heme-containing oxygenases [J]. Chem Rev, 1996, 96: 2841-2888

[9] TrindadeA F, GoisM P, AfonsoA M. Recyclable stereoselective catalysts [J]. Chem Rev, 2009, 109: 418-514

[10] McdonaldA R, FranssenN, KlinkG P M, KotenG. ‘Click’ silica immobilisation of metallo-porphyrin complexes and their application in epoxidation catalysis [J]. Organomet Chem, 2009, 694: 2153-2162

[11] TatsumiT, NakamuraM, TominagaH. Hydroxylation of alkanes catalyzed by manganese tetraphenylporphyrin immobilized on imidazole-modified silica gel [J]. Chem Lett, 1989, 18: 419-420

[12] FuB, YuH, HuangJ, ZhaoP, LiuJ, JiL. Mn(III) porphyrins immobilized on magnetic polymer nanospheres as biomimetic catalysts hydroxylating cyclohexane with molecular oxygen[J]. Mol Catal A: Chem, 2009, 298: 74-80

[13] FuB, ZhaoP, YuH, HuangJ, LiuJ, JiL. Magnetic polymer nanospheres immobilizing metalloporphyrins catalysis and reuse to hydroxylate cyclohexane with molecular oxygen [J]. Catal Lett, 2009, 127: 411-418

[14] AstudilloJ, AguilaG, DiazF, GuerreroS, ArayaP. Study of CuO-CeO₂ catalysts supported on SiO₂ on the low-temperature oxidation of CO [J]. Appl Catal A: Gen, 2010, 381: 169-176

[15] ShanW, ShenW, LiC. Structural characteristics and redox behaviors of Ce_1−xCu_xO_y solid solutions [J]. Chem Mater, 2003, 15: 4761-4767

[16] AdamF, KuehC W, NgE P. The immobilization of iron(III) aminopyridine complex on MCM-41: Its preparation and characterization [J]. J Porous Mater, 2013, 20: 1337-1343

[17] MilaevaE R, GerasimovaO A, MaximovA L, IvanovaE A, KarachanovE A, HadjiliadisN, LouloudiM. The catalytic activity of immobilized on modified silica metalloporphyrins bearing antioxidative 2,6-di-tert-butylphenol pendants [J]. Catal Commun, 2007, 8: 2069-2073

[18] GhiaciM, MolaieF, SedaghatM E, DorostkarN. Metalloporphyrin covalently bound to silica. Preparation, characterization and catalytic activity in oxidation of ethyl benzene [J]. Catal Commun, 2010, 11: 694-699

[19] ZhaiY, TuB, ZhaoD. Organosilane-assisted synthesis of ordered mesoporous poly(furfuryl alcohol) composites [J]. J Mater Chem, 2009, 19: 131-140

[20] LiuC, LiuQ, GuoC. Synthesis and catalytic abilities of silica-coated Fe₃O₄ nanoparticle bonded metalloporphyrins with different saturation magnetization [J]. Catal Lett, 2010, 138: 96-103

[21] ZhangJ, ThurberA, HannaC. Highly shape-selective synthesis, silica coating, self-assembly, and magnetic hydrogen sensing of hematite nanoparticles [J]. Langmuir, 2010, 26: 5273-5278

[22] ZhangJ, LiuH, WangZ, MingN. Au-induced polyvinylpyrrolidone aggregates with bound water for the highly shape-selective synthesis of silica nanostructures [J]. Chem Eur J, 2008, 14: 4374-4380

[23] GuoC, LiuC, LiuQ. Preparation and characterization of novel magnetic nanocomposite-bonded metalloporphyrins as biomimetic nanocatalysts [J]. J Porphyrins Phthalocyanines, 2010, 14: 825-831

[24] LiuZ, ZhouR, ZhengX. Comparative study of different methods of preparing CuO-CeO₂ catalysts for preferential oxidation of CO in excess hydrogen [J]. J Mol Catal A: Chem, 2007, 267: 137-142

[25] GrassetF, MarchandR, MaricA M, FauchadourD, FajardieF. Synthesis of CeO₂@SiO₂ core-shell nanoparticles by water-in-oil microemulsion: Preparation of functional thin film [J]. J Colloids Interface Sci, 2006, 299: 726-732

[26] CastroK A D F, BailA, GroszewiczP B, MachadoG S, SchreinerW H, WypychF, NakagakiS. New oxidation catalysts based on iron(III) porphyrins immobilized on Mg-Al layered double hydroxides modified with triethanolamine [J]. Appl Catal A: Gen, 2010, 386: 51-59

[27] HeckJ V, ChrisrensenB G. Nuclear analogs of β-lactam antibiotics I: The synthesis of 6β-amidocyclonocardicins [J]. Tetra Lett, 1981, 22: 5027-5030

[28] HuangG, LiT, LiuS, FanM, JiangY, GuoY. A robust boehmite-supported cobalt tetraphenylporphyrin catalyst for aerobic oxidation of cyclohexane [J]. Appl Catal A: Gen, 2009, 37: 161-165

[29] ChoW S, KimH J, LittlerB J, MillerM A, LeeC H, LindseyJ S. Rational synthesis of trans-substituted porphyrin building blocks containing one sulfur or oxygen atom in place of nitrogen at a designated site [J]. J Org Chem, 1999, 64: 7890-7901

[30] CostaA A, GhestiG F, MacedoJ L, BragaV S, SantosM M, DiasJ A, DiasS C L. Immobilization of Fe, Mn and Co tetraphenylporphyrin complexes in MCM-41 and their catalytic activity in cyclohexene oxidation reaction by hydrogen peroxide [J]. J Mol Catal A: Chem, 2008, 282: 149-157

[31] XieJ, WangY, WeiYu. Immobilization of manganese tetraphenylporphyrin on Au/SiO₂ as new catalyst for cyclohexane oxidation with air [J]. Catal Commun, 2009, 11: 110-111