(728d) Hierarchical LTA Zeolites with Amine-Functionalized Mesoporous Domain for Post-Combustion Carbon Dioxide Capture

Owing to global concern on climate change caused by rising atmospheric CO₂ concentration, the technologies for capturing CO₂ from anthropogenic sources, such as coal-fired power plants, have attracted a great amount of interests. Among various methods available, capturing CO₂ with solid adsorbents has been considered as an energy-efficient alternative to conventional amine scrubbing that consumes a large amount of energy for the regeneration of media. Efforts to develop solid adsorbents performing at conditions relevant to the flue gas released from coal-fired power plants lead to synthesis of various alkylamine-functionalized mesoporous materials including MCM-41 and SBA-15. Even though amine groups in such materials can effectively capture CO₂ molecules, the substrates typically have thick pores walls that cannot contribute to CO₂ uptake while increasing the mass of sorbent. Thus, optimizing the substrate structure can significantly improve the CO₂ uptake property of resultant materials.

  In this work, we synthesized hierarchical LTA zeolites containing amine-functionalized mesoporous domain. Gas adsorption study revealed that CO₂ molecules are effectively captured by both alkylamine groups in the mesopore domain and active sites in the LTA zeolite. Hence, the amount of CO₂ uptake on this material was much greater than that for conventional aminosilicas at the conditions relevant to post-combustion CO₂ capture.