Probing the Role of Zr Addition versus Textural Properties in Enhancement of CO ₂ Adsorption Performance in Silica/PEI Composite Sorbents

Journal Article · Sat Aug 08 00:00:00 EDT 2015 · Langmuir

DOI:https://doi.org/10.1021/acs.langmuir.5b02114· OSTI ID:1286962

Sakwa-Novak, Miles A. ^[1]; Holewinski, Adam ^[1]; Hoyt, Caroline B. ^[1]; Yoo, Chun-Jae ^[1]; Chai, Song-Hai ^[2]; Dai, Sheng ^[3]; Jones, Christopher W. ^[1]

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1. Georgia Inst. of Technology, Atlanta, GA (United States)
2. Univ. of Tennessee, Knoxville, TN (United States)
3. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Polymeric amines such as poly(ethylenimine) (PEI) supported on mesoporous oxides are promising candidate adsorbents for CO₂ capture processes. One important aspect to the design and optimization of these materials is a fundamental understanding of how the properties of the oxide support such as pore structure, particle morphology, and surface properties affect the efficiency of the guest polymer in its interactions with CO₂. Previously, the efficiency of impregnated PEI to adsorb CO₂ was shown to increase upon the addition of Zr as a surface modifier in SBA-15. But, the efficacy of this method to tune the adsorption performance has not been explored in materials of differing textural and morphological nature. These issues are directly addressed via the preparation of an array of SBA-15 support materials with varying textural and morphological properties, as well as varying content of zirconium doped into the material. Zirconium is incorporated into the SBA-15 either during the synthesis of the SBA-15, or postsynthetically via deposition of Zr species onto pure-silica SBA-15. The method of Zr incorporation alters the textural and morphological properties of the parent SBA-15 in different ways. Importantly, the CO₂ capacity of SBA-15 impregnated with PEI increases by a maximum of ~60% with the quantity of doped Zr for a “standard” SBA-15 containing significant microporosity, while no increase in the CO₂ capacity is observed upon Zr incorporation for an SBA-15 with reduced microporosity and a larger pore size, pore volume, and particle size. Finally, adsorbents supported on SBA-15 with controlled particle morphology show only modest increases in CO₂ capacity upon inclusion of Zr to the silica framework. The data demonstrate that the textural and morphological properties of the support have a more significant impact on the ability of PEI to capture CO₂ than the support surface composition.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Energy Frontier Research Centers (EFRC) (United States). Center for Understanding and Control of Acid Gas-induced Evolution of Materials for Energy (UNCAGE-ME)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC05-00OR22725; SC0012577
• OSTI ID: 1286962
• Journal Information: Langmuir, Vol. 31, Issue 34; ISSN 0743-7463
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE