Silicoaluminophosphates as CO 2 sorbents

Ocean Cheung, Qingling Liu, Zoltán Bacsik, Niklas Hedin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

66 Citations (SciVal)


Silicoaluminophosphates (SAPO-17, SAPO-35, SAPO-56 and SAPO-RHO) synthesised via hydrothermal means are tested for their abilities to adsorb carbon dioxide. These 8-ring microporous phosphates show high capacities to adsorb CO 2. SAPO-RHO has a high uptake of CO 2 and a very low uptake of N 2 due to its narrow pore window aperture at 273 K. Its significant uptake of N 2 at 77 K is rationalised by a temperature induced shrinkage effect. SAPO-56 has a slightly higher CO 2 capacity (5.42 mmol/g, 273 K, 101 kPa) and is less water sensitive than zeolite 13X. Cyclic adsorption and in situ infrared spectroscopy (IR) reveal that SAPOs retain 95% of their original CO 2 capacity after six cycles and that adsorption occurs via physisorption. The calculated heat of adsorption for CO 2 (at 0.2-0.7 mmol/g loading) on SAPO-56 and SAPO-RHO lies in the physisorption range (∼35 kJ/mol). SAPOs, in particular SAPO-56 and SAPO-RHO, possess many desirable properties and are potentially good adsorbents for CO 2 capture in swing adsorption processes.

Original languageEnglish
Pages (from-to)90-96
Number of pages7
JournalMicroporous and Mesoporous Materials
Publication statusPublished - 1 Jul 2012


  • Adsorption
  • Carbon capture
  • Carbon dioxide
  • SAPO-56
  • Silicoaluminophosphates

ASJC Scopus subject areas

  • General Materials Science
  • Mechanics of Materials
  • General Chemistry
  • Condensed Matter Physics


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