Tracking carbon dioxide adsorbate intramolecular dynamics in pure silica zeolite Silicalite-1 by in situ Raman scattering.

We report a series of high-quality Raman spectra of carbon dioxide (CO2) adsorbed at room temperature and at various equilibrium pressures, sampling the corresponding adsorption isotherm up to 12 bar. The observed splitting in Fermi diad resonance lines, which were additionally split into two well-resolved components, arising from at least two different CO2 species, were compared to the same quantity in high-pressure gas/solid/liquid CO2 phases. Our studies provide material specific spectral data that could be useful in the detection, identification, and dynamical characterization of CO2 deposits, inclusions, or other forms in remote locations and of various origins, e.g. geological, planetary, stellar, and deap-sea sediments.