TEMPERATURE-SWING SORPTION DESORPTION CYCLES OF NITRIC-OXIDE THROUGH INTERCALATION BY DOUBLE-LAYERED CUPRATE/

Temperature-swing sorption/desorption cycles of dilute NO over a doubl e layered cuprate, La1.4Ba0.6SrCu2O6, were carried out in a convention al flow reactor between 250 degrees C (sorption step) and 500-700 degr ees C (desorption step). The desorption step in a dry atmosphere remov ed the interlayer hydroxyls, which play a key role in promoting NO int ercalation, and thereby destroyed NO absorbability. Stable and reversi ble sorption/desorption cycles were successfully achieved in the prese nce of water vapor (0.7%), which readily regenerates the interlayer hy droxyls in a sorption step. In this case, the intercalated NO was imme diately condensed out of the stream at the beginning of each desorptio n step. The regenerative capacity for NO was equal to the maximum upta ke after given time of sorption. The NO desorption was accompanied by the considerable formation of N-2 as a result of dissociative desorpti on of intercalated NO. Repeating sorption/desorption cycles supposedly produces a new interlayer site active for the dissociative NO desorpt ion at lower temperatures (ca. 350 degrees C). (C) 1998 Elsevier Scien ce B.V. All rights reserved.