Mesoporous ferromagnetic MPt@Silica/Carbon (M = Fe, Co, Ni) composites As advanced bifunctional catalysts

Emanuel Kockrick, Franz Schmidt, Kristina Gedrich, Marcus Rose, Thomas A. George, Thomas Freudenberg, Ralph Kraehnert, Ralph Skomski, David J. Sellmyer, Stefan Kaskel

Research output: Contribution to journalArticle

25 Scopus citations

Abstract

Ferromagnetic MPt (Fe, Co, Ni) nanocomposites were obtained by infiltration of aqueous and chloroform precursor solutions into ordered mesoporous SBA-15 and CMK-3. Channel-confined crystallization of the intermetallic phases was achieved under a reductive and inert atmosphere in a temperature range from 673 to 1073 K using conventional and ultrafast IR furnace heating. The proper choice of mesoporous matrix allows one to tailor crystallite size and to affect the phase transformation rate into ordered face-centered tetragonal (fct) MPt alloys. XRD and TEM techniques were used to monitor the structural evolution in the system. Physisorption methods reveal degradation of the mesoporous carbon matrix for MPt@CMK-3 composites while SBA-15 templated structures stay intact. SQUID investigations were carried out, demonstrating a strong dependence of magnetic properties on the intermetallic system, matrix, and treatment conditions. Especially for fct FePt@carbon, very high room-temperature coercivities up to 28.4 kOe were observed. The materials are efficient catalysts for acetylene to ethylene hydrogenation. Structuresensitive selectivity of FePt is reported for the first time, demonstrating a higher selectivity of fct FePt composites as compared to the disordered face-centered cubic (fcc) phase.

Original languageEnglish (US)
Pages (from-to)1624-1632
Number of pages9
JournalChemistry of Materials
Volume22
Issue number5
DOIs
StatePublished - Mar 9 2010

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

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    Kockrick, E., Schmidt, F., Gedrich, K., Rose, M., George, T. A., Freudenberg, T., Kraehnert, R., Skomski, R., Sellmyer, D. J., & Kaskel, S. (2010). Mesoporous ferromagnetic MPt@Silica/Carbon (M = Fe, Co, Ni) composites As advanced bifunctional catalysts. Chemistry of Materials, 22(5), 1624-1632. https://doi.org/10.1021/cm9016276