XRD characterization of highly dispersed metal catalysts on carbon support
作者： Paolo Scardi , Pier Luigi Antonucci
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摘要: aqueous solutions.Particle size and structure after several thermal activation treatments were studiedby X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), CyclicVoltammetry (CV), the results of three techniques compared. As thecatalysts highly dispersed on an amorphous support, a conventional XRD profileanalysis for crystallite determination could not be performed properly, becauseof strong overlapping between broad Pt peaks superposed to halos theamorphous phase. Thus, new procedure whole pattern fitting, based theRietveld method, was used have reliable data particle (surface area) andlattice parameter. All structural microstructural parameters refined within thesame procedure, also considering transparency carbon supported catalystsand minimizing effect background. The method can takeinto account presence bimodal distributions, which is difficult tostudy by CV or TEM.I. INTRODUCTIONSolid-state characterization metal crys-tallites paramount significance knowledgeof structure-property relationships, with particularemphasis that directly linked catalytic phe-nomenon. Information crystallites' anddistribution is, in this respect, essential as these pa-rameters strongly influence degree metal-supportinteraction due sensitivity effects, espe-cially when said materials are employed fordemanding (structure sensitive) reactions
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