Phosphorus poisoning and regeneration of the Cu-LTA catalyst for the selective catalytic reduction of NOx with NH3

Abstract

In this study, the phosphorus poisoning and regeneration of the Cu-LTA catalyst for the selective catalytic reduction of NO_x with NH₃ (NH₃-SCR) were investigated. Since Cu-LTA possesses high hydrothermal stability, harsh conditions can be used for the regeneration of phosphorus-poisoned Cu-LTA. It was found that the phosphorus-poisoned Cu-LTA can totally recover its low-temperature activity by hydrothermal aging at 900 °C for 1 h owing to the decomposition of Cu–P species. The influence of the gas composition of the atmosphere during the formation and regeneration of Cu–P species has not been reported yet, while we found that the O₂ and H₂O in the atmosphere have negative and positive effects on the decomposition of Cu–P species, respectively. Thus, the reduction of O₂ in the atmosphere promoted the decomposition of Cu–P species and reduced the temperature needed for the regeneration of phosphorus-poisoned Cu-LTA. This work further proved the great potential of Cu-LTA for practical applications.