| 摘要 |
<p>The present invention relates to a copper containing ZSM-34, OFF and/or ERI zeolitic material having a silica to alumina mole ratio ranging from about 4 to about 50 and a copper content, reported as Cu O, ranging from about 1 to about 10 wt.-%, based on the total weight of the cal- cined zeolitic material, and having an alkali metal content, reported as the metal oxide, ranging from about 0.7 to about 1.5 wt.-%, whereas the 750°C-aged copper containing ZSM-34, OFF and/or ERI zeolitic materialexhibits NO conversion at 200°C of at least about 75 % and at 450°C of at least about 90 %, measured at a gas hourly volume based space velocity of 30000 h - under steady state conditions at maximum NH 3 -slip conditions in a gas mixture of 500 ppm NO, 500 ppm NH 3, 10% O 2, 5% H 2 O, balance N</p> |
