Temperature-swing sorption/desorption cycles of nitric oxide through intercalation by double layered cuprate

Abstract

Temperature-swing sorption/desorption cycles of dilute NO over a double layered cuprate, La 1.4Ba 0.6SrCu 2O 6, were carried out in a conventional flow reactor between 250°C (sorption step) and 500–700°C (desorption step). The desorption step in a dry atmosphere removed the interlayer hydroxyls, which play a key role in promoting NO intercalation, and thereby destroyed NO absorbability. Stable and reversible sorption/desorption cycles were successfully achieved in the presence of water vapor (0.7%), which readily regenerates the interlayer hydroxyls in a sorption step. In this case, the intercalated NO was immediately condensed out of the stream at the beginning of each desorption step. The regenerative capacity for NO was equal to the maximum uptake after given time of sorption. The NO desorption was accompanied by the considerable formation of N 2 as a result of dissociative desorption of intercalated NO. Repeating sorption/desorption cycles supposedly produces a new interlayer site active for the dissociative NO desorption at lower temperatures (ca. 350°C).