263784 Contracted Titanium Silicate (CTS-1): Aspects of Structure and CO2 Sorption

Tuesday, October 30, 2012
Hall B (Convention Center )
Ocean Cheung, Jing Li, Jie Su, Zoltan Bacsik, Xiaodong Zou and Niklas Hedin, Department of Materials and Environmental Chemistry, The Berzelii Center EXSELENT on Porous Materials, Stockholm University, Stockholm, Sweden

Engelhard Titanium Silicates (ETS) is a family of microporous titanium silicate materials first reported in 1989. Since then some variants were studied or implemented in applications. The Molecular GateTM technology can be used to upgrade CH4 from mixtures of CH4, N2, and CO2. It operates with a contracted titanium silicate (CTS-1) sorbent that relates to ETS-4. Surprisingly little is known for the structure and properties of such CTS-1 sorbents. We examined the potential of alkaline earth exchanged CTS-1 as sorbents for CO2. All tested materials showed excellent levels of CO2 uptake at 273 K. In particular, Mg2+ exchanged CTS-1 had high preferential CO2 uptake (2.16 mmol/g, 273 K) with an ideal CO2-over-N2 selectivity of 14. CO2 physisorbed rapidly with rates relevant for swing adsorption processes (80% of maximum capacity was reached in 45 seconds). We followed CO2 sorption on Mg-CTS-1 by in situ infrared spectroscopy and characterized the physis- and chemisorbed CO2 species. Vacuum and heat induced transformation of ETS-4 into CTS-1. In situ X-ray powder diffraction and electron diffraction were used to establish unit cell parameters of Mg-CTS-1. In summary, we showed that Mg-CTS-1 could potentially be a highly selective sorbent for carbon capture.

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