THE DESORPTION OF O-2 DURING NO AND N2O DECOMPOSITION ON CU-ZEOLITES AND FE-ZEOLITES

The decomposition of NO and of N2O over a CuZSM-5 zeolite and a Fe-mordenite, respectively, has been studied using tracer techniques. The results demonstrate the high mobility of the lattice oxygen ions in self-diffusion. They afford a possible explanation for the problem of how two extralattice oxygens located at positions remote from each other may combine to form the O-2 molecules which are spontaneously desorbed in these redox reactions. They show that a portion of the lattice oxygen mixes into the O-2 released on decomposition. The data also show that (NO)-O-18 and (N2O)-O-18 undergo exchange with the catalyst oxygen under reaction conditions.