In addition to the chemical and engineering complications that exist with integrated catalysis, there is also an analytical challenge to address when catalysts are spatially confined. For homogeneous catalytic systems, the characterization methods are diverse and often diagnostic, such as NMR spectroscopy and X-ray crystallography. However, when the catalyst is compartmentalized or immobilized on a solid surface, the system becomes complex, and the aforementioned methods are usually no longer applicable. Some spectroscopic methods such as X-ray photoelectron spectroscopy, inductively coupled plasma mass spectrometry, and inductively coupled plasma -optical emission spectrometry can be used to obtain elemental information either for the surface or the bulk powder. Infrared, Raman, and absorption spectroscopy can facilitate the understanding of the catalyst's nature. However, additional characterization methods are necessary for a detailed and precise chemical structure of the catalytic system that would ensure reproducibility.