Advanced techniques such as X-Ray Photoelectron Spectroscopy (XPS), In Situ Spectroscopy, and High-Resolution Electron Microscopy (HREM) are also gaining prominence. XPS provides information on the surface composition and oxidation states of elements. In situ spectroscopy techniques, such as In Situ XRD and In Situ IR, allow for real-time monitoring of catalytic reactions. HREM offers atomic-level resolution, enabling the study of catalyst structure in great detail.