Catalytic decomposition of NO over brownmillerite-like compounds, Ca 2Fe 2O 5 and Sr 2Fe 2O 5

Abstract

A high-temperature form of a brownmillerite-like compound Sr 2Fe 2O 5, which has a perovskite structure with the oxygen vacancies randomly distributed, showed a remarkable NO decomposition at 700–900°C, whereas another brownmillerite-like ferrate (III) of composition Ca 2Fe 2O 5 did not exhibit any significant catalytic activity for NO decomposition over the temperature range from room temperature to 900°C. This difference in their catalytic activities has been explained on the basis of their crystallographic properties, i.e., ordering or disordering of the oxygen deficiencies.