Exceptional Packing Density of Ammonia in a Dual-Functionalized Metal–Organic Framework

Research output: Contribution to journalArticlepeer-review

  • External authors:
  • Christopher Marsh
  • Jiangnan Li
  • Zhenzhong Lu
  • Stephen P. Argent
  • Ivan Da Silva
  • Yongqiang Cheng
  • Luke L. Daemen
  • Anibal J. Ramirez-cuesta
  • Stephen P. Thompson
  • Alexander J. Blake


We report the reversible adsorption of ammonia (NH3) up to 9.9 mmol g–1 in a robust Al-based metal–organic framework, MFM-303(Al), which is functionalized with free carboxylic acid and hydroxyl groups. The unique pore environment decorated with these acidic sites results in an exceptional packing density of NH3 at 293 K (0.801 g cm–3) comparable to that of solid NH3 at 193 K (0.817 g cm–3). In situ synchrotron X-ray diffraction and inelastic neutron scattering reveal the critical role of free −COOH and −OH groups in immobilizing NH3 molecules. Breakthrough experiments confirm the excellent performance of MFM-303(Al) for the capture of NH3 at low concentrations under both dry and wet conditions.

Bibliographical metadata

Original languageEnglish
Pages (from-to)6586-6592
JournalJournal of the American Chemical Society
Issue number17
Publication statusPublished - 22 Apr 2021