DECOMPOSITION OF NO OVER CU-ZSM-5 PREPARED BY SOLID-STATE ION-EXCHANGE

Cu,H-ZSM-5 (Cu/H = 1.5) prepared by solid-state ion exchange with exce ss CuCl proved to be, after reduction with CO at 500 degrees C, highly active in NO decomposition even at reaction temperatures below 300 de grees C, while reduction with hydrogen resulted in a catalyst which wa s much less active below 450 degrees C but highly active at about 500 degrees C. These phenomena are interpreted in terms of the role of Cu lattice cations and Bronsted acid sites involved in the mechanism of the catalytic reaction.