Removal of Nitrogen Monoxide through a Novel Catalytic Process. 1. Decomposition of Excessively Copper Ion Exchanged ZSM-5 Zeolites

Article abstract of DOI:10.1021/j100162a053

Repeated ion exchange of the ZSM-5 zeolite aqueous copper(II) acetate solution was found to bring about excess loading of copper ions above an exchange level of 100percent.The high activity of the resulting catalyst for NO decomposition was consistent for at least 30 h even at short contact time and low NO pressure.The number of copper ions that can absorb NO molecules has been determined by a temperature-programmed desorption technique combined with IR measurement; 94percent of Cu²⁺ ions in ZSM-5 were active for the adsorption.The activity of excessively copper ion exchangedZSM-5 zeolite was slightly reduced by the oxygen in the feed gas while that of the zeolite, of which the loading amount of copper was less than 100percent, was greatly diminished under the same condition.SO2 completely poisons the activity at 673-923 K, but the activity can be regenerated at the higher temperature treatment.