Particle size distribution of Pd on silica

Small Angle X-ray Scattering (SAXS) is a powerful technique to measure particle size in nanomaterials. In general the technique measures and models diffuse X-ray scattering at very low angle caused by electron density fluctuations in the material under study. In the case of particle size measurements the electron density fluctuation is caused by the presence of particles and their surrounding voids within the sample. The scattering can be interpreted by modeling the particle size, calculating the expected data, and refining the model such that the calculated data best matches the experimental curve.

Palladium (Pd) on silica is a well known heterogeneous catalyst in many industrial processes, such as hydrogenation. An extremely important parameter for controlling the activity of the catalyst is its particle size.

Figure 1 depicts the SAXS data collected from a Pd on silica catalyst using Rigaku's Ultima IV multipurpose diffraction system configured for SAXS measurements.

SAXS data collected from a Pd on silica catalys
Figure 1

Figure 2 displays the calculated SAXS data from the final particle size distribution model refined to fit the experimentally collected data.

SAXS data collected from a Pd on silica catalys
Figure 2

Figure 3 shows the final particle size distribution used to calculate the refined data.

final particle size distribution
Figure 3

Ultima IVThe Ultima IV represents the state-of-the-art in multipurpose X-ray diffraction (XRD) systems. Incorporating Rigaku's patented cross beam optics (CBO) technology for permanently mounted, permanently aligned and user-selectable parallel and focusing geometries, the Ultima IV X-ray diffractometer can perform many different Read more about Rigaku's Ultima IV...

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