Small-angle X-ray scattering intensity of multiscale models of spheroids

The microstructure of heterogeneous catalysts often consists of multiscale aggregates of nanoparticles, some of which are highly anisotropic. Therefore, small-angle X-ray scattering, in classical or anomalous mode, is a valuable tool to characterize this kind of material. Yet, the classical exploitation of the scattered intensities through form and structure factors or by means of Boolean models of spheres is questionable. Here, it is proposed to interpret the scattered intensities through the use of multiscale Boolean models of spheroids. The numerical procedure to compute scattered intensities of such models is given and then validated on asymptotic diluted Boolean models, and its applicability is demonstrated for the characterization of alumina catalyst supports.

Automated summary

The microstructure of heterogeneous catalysts, composed of multiscale aggregates of anisotropic nanoparticles, can be effectively characterized using small-angle X-ray scattering. Instead of traditional methods, this study proposes the use of multiscale Boolean models of spheroids to interpret the scattered intensities. The numerical procedure for computing the scattered intensities is validated on asymptotic diluted Boolean models and successfully applied to characterize alumina catalyst supports.