Understanding the Dynamics of Nanoparticle Formation and Evolution in Functional Oxides via In Situ SAXS/WAXS

The formation and evolution of nanoparticles on the surface of oxide catalysts are essential for determining their catalyticperformance. Establishing a direct relationship between structure and function requires real-time in situ characterization underoperational conditions. Multiple techniques can be used to create catalytically active nanoparticles on catalyst surfaces, includingtraditional deposition or infiltration methods and novel techniques such as exsolution, which allows the in situ growth of stableparticles. In this study, we report the first in situ Small-Angle and Wide-Angle X-ray Scattering (SAXS/WAXS) investigationof Ni nanoparticle formation in La0.85Sr0.15Cr0.8Ni0.2O3-δ (LSCN), where particles emerge via exsolution, and in a referenceLa0.85Sr0.15CrO3-δ sample with infiltrated Ni (LSC+5N), at synchrotron facilities. The results reveal early nucleation and thermalevolution with high sensitivity and statistical robustness. By tracking nanoparticle formation and evolution during reduction atincreasing temperatures, SAXS provides a complementary tool to conventional techniques such as XRD and electron microscopyfor real-time monitoring. This study establishes SAXS/WAXS as a powerful and innovative tool for investigating nanoscaleprocesses in functional ceramic materials, offering new insights into the design of stable and active nanostructured catalysts.