Silver-functionalized silica aerogel: towards an understanding of aging on iodine sorption performance

摘要: The silver-functionalized silica aerogel (Ag0-aerogel) is being developed for the removal and sequestration of iodine compounds from off-gas a nuclear fuel reprocessing plant. This material shows high selectivity sorption capacity iodine. However, its performance decreases when exposed to air containing H2O NOx at 150 °C extended periods time. phenomenon referred as “aging” simulates exposure sorbent during plant idling. extensive study unaged aged samples Ag0-aerogel with without revealed that decreased efficiency I capture after NO-aging can be attributed an increase in size silver nanoparticles by formation free sulfate on their surfaces oxidized thiol groups. smaller reactive surface areas bigger particles thin layer particle prevented complete utilization silver. By contrast, appears main factor decreasing dry or humid air. It hypothesized short period reducing gas stream would reduce back metal sulfide. may recover close original levels.