Highly sinter-stable metal nanoparticles supported on mesoporous graphitic particles and their use
AssigneeStudiengesellschaft Kohle mbH
InventorsFerdi Schüth, Diana Carolina Galeano Nunez, Hans-Josef Bongard, Karl Mayrhofer, Josef C. Meier, Claudio Baldizzone, Stefano Mezzavilla
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Abstract
The present invention refers to highly sinter-stable metal nanoparticles supported on mesoporous graphitic spheres, the so obtained metal-loaded mesoporous graphitic particles, processes for their preparation and the use thereof as catalysts, in particular for high temperature reactions in reducing atmosphere and cathode side oxygen reduction reaction (ORR) in PEM fuel cells.
Claims18
Process for preparing highly sinter-stable metal nanoparticles supported on mesoporous graphitic particles, said process comprising the steps of:
- a. impregnating particles having a porous basic framework with a graphitizable organic compound to yield impregnated particles,
- b. subjecting the impregnated particles obtained in step a) to a high temperature graphitization process, whereby graphitized particles having a graphitic framework in the porous basic framework are provided,
- c. subjecting the graphitized particles obtained in step b) to a process for removing the porous basic framework, whereby mesoporous graphitic particles having a mesoporous graphitic framework are provided,
- d. impregnating the mesoporous graphitic particles obtained in step c) with at least one catalytically active metal selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Mo, Se, Sn, Pt, Ru, Pd, W, Ir, Os, Rh, Nb, Ta, Pb, Bi, Au, Ag, Sc, Y and salts and mixtures thereof to yield impregnated mesoporous graphitic particles,
- e. subjecting the impregnated mesoporous graphitic particles obtained in step d) to a hydrogenation process to yield metal-loaded impregnated mesoporous graphitic particles having catalytically active metal sites in mesopores of the metal-loaded impregnated mesoporous graphitic particles, and
- f. subjecting the metal-loaded impregnated mesoporous graphitic particles obtained in step e) to a high temperature treatment in a high temperature range from 600° to 1400° C., and optionally in an inert atmosphere.
Process for preparing highly sinter-stable metal nanoparticles supported on mesoporous graphitic bodies comprising the steps of
- a. treating mesoporous graphitic particles with a solution of at least one catalytically active metal salt, selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Mo, Se, Sn, Pt, Ru, Pd, W, Ir, Os, Rh, Nb, Ta, Pb, Bi, Au, Ag, Sc, Y, and mixtures thereof, optionally via an impregnation step where a volume of a solution of the metal salt(s) is completely absorbed in mesopores of the mesoporous graphitic particles, and optionally further dispersing metal contained in said solution in mesopores of said mesoporous graphitic particles by ultrasonification, and finally drying under an inert atmosphere to yield metal salt-loaded particles,
- b. subjecting the metal salt-loaded particles obtained in step a) to a hydrogenation process to remove any salt residue, and drying to yield metal-loaded particles, and c. thermally treating the metal-loaded particles obtained in step b) in a temperature range of 600° to 1400° C., to confine the metal nanoparticles in mesopores of the metal-loaded particles.
Mesoporous graphitic bodies having highly sinter-stable metal nanoparticles in an interconnected mesoporous 3D structure, said metal nanoparticles being catalytically active and confined in the interconnected 3D mesoporous structure, and wherein said metal is selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Mo, Se, Sn, Pt, Ru, Pd, W, Ir, Os, Rh, Nb, Ta, Pb, Bi, Au, Ag, Sc, Y, and mixtures thereof.
Dependencies are inferred from the claim text.