Structural effects on the high temperature adsorption of CO2 on a synthetic hydrotalcite

Nick D. Hutson, Scott A. Speakman, E. Andrew Payzant

Research output: Contribution to journalArticlepeer-review

190 Scopus citations

Abstract

Hydrotalcite-like compounds (HTlcs) are solid sorbents that may potentially be used for high-temperature separation and capture of CO2. The high-temperature adsorption of CO2 on Mg-Al-CO3 HTlc is affected by structural changes that take place upon heating of the material. The structural changes of a synthetic HTlc upon heating to 200 and 400 °C in a vacuum were characterized using various analytical techniques. These structural changes were then related to observed behavior with respect to the physisorption and chemisorption of CO2 at 200 °C. Upon heating to 200 °C, the material retains its layered structure, though the interlayer spacing is decreased by ∼0.6 Å due to loss of interlayer water. Chemisorption of CO2 at 200 °C represents more than half of the total adsorption capacity (at 107 kPa) due to increased availability of the framework Mg 2+ cation and the subsequent formation of MgCO3. There is no significant increase of surface area or pore volume after heating to 200 °C. Upon heating to 400 °C the CO32- in the interlayer is decomposed and the material is completely dehydrated and partially dehydroxylated. The resulting amorphous 3-D structure with increased surface area and pore volume and decreased availability of the Mg2+ cation favors physisorption over chemisorption for these samples. An increased understanding of structure-property relationships will help in the further development of HTlcs as viable CO2 solid sorbents.

Original languageEnglish
Pages (from-to)4135-4143
Number of pages9
JournalChemistry of Materials
Volume16
Issue number21
DOIs
StatePublished - Oct 19 2004
Externally publishedYes

Fingerprint

Dive into the research topics of 'Structural effects on the high temperature adsorption of CO2 on a synthetic hydrotalcite'. Together they form a unique fingerprint.

Cite this