title: Radioactive iodine capture in silver-containing mordenites through nanoscale silver iodide formation.
abstract: The effective capture and storage of radiological iodine ((129)I) remains a strong concern for safe nuclear waste storage and safe nuclear energy. Silver-containing mordenite (MOR) is a longstanding benchmark for iodine capture; however, the molecular level understanding of this process needed to develop more effective iodine getters has remained elusive. Here we probe the structure and distribution of iodine sorbed by silver-containing MOR using differential pair distribution function analysis. While iodine is distributed between gamma-AgI nanoparticles on the zeolite surface and subnanometer alpha-AgI clusters within the pores for reduced silver MOR, in the case of unreduced silver-exchanged MOR, iodine is exclusively confined to the pores as subnanometer alpha-AgI. Consequently, unreduced silver-containing zeolites may offer a more secure route for radioactive iodine capture, with the potential to more effectively trap the iodine for long-term storage.
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA. chapmank@aps.anl.gov
authors.forename: Karena W
authors.initials: KW
authors.lastname: Chapman
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Chupas
authors.forename: Tina M
authors.initials: TM
authors.lastname: Nenoff