It is the purpose of this Letter to announce the development of a zeolitic catalyst that is more active than CuZSM-5, durable, and free from poisoning by H2O and/or SO2. Therefore it may be of practical value in combustion catalysis. A preliminary report is given here; a more detailed one will follow shortly. The catalyst is an "overexchanged" FeZSM-5 made from NaZSM-5 in a special way to minimize H+-bearing AlO2- sites.