A novel three-dimensional information imaging, spin exchange rate (SER) spectra, was proposed to use for the analysis of complicated molecular motions of gaseous molecules in powder solids. It has successfully been applied to characterize molecular dynamics of NO2 on Na-mordenite. This spectrum directly illustrates the detailed dynamic information of motion of NO2 versus temperature, which showed that (1) the molecular motion of NO2 is a superposition of individual motions, corresponding to different spin exchange rates; (2) for a given temperature, there is a dominant spin exchange rate and the rate increases with increasing temperature; (3) the distribution of active spin exchange rates is broadened with increasing temperature and then decreases again at higher temperature; and (4) there are two different dynamical processes in the temperature range 110-260 K : one with an activation energy of 486 J/mol is attributed to adsorption; the other with 4390J/mol is a desorption process, and they reach adsorption-desorption equilibrium. Theoretical interpretations of these observations are also given in this paper.