Diammonium-Pillared MOPS with Dynamic CO2 Selectivity

Abstract

Summary: The climate challenge calls for the design of energy-efficient CO2-separation materials. CO2-selective solid physisorbents are characterized by a low energy penalty and enable the most promising and energy-efficient CO2 separation technologies by applying vacuum swing adsorption (VSA). Here, we show that a diammonium-pillared microporous organically pillared layered silicate 7 (MOPS-7) represents a CO2-selective physisorbent, synthesized by simple ion exchange of an inexpensive clay. This MOPS provides high dynamic, reversible, and reproducible CO2 uptakes and selectivities proven in dynamic breakthrough experiments mimicking flue gas, natural gas, and biogas conditions. The selective interaction with CO2 is dominated by the multipole interactions with the microporous hybrid material. Thus, the energy penalty attributed to regeneration is intrinsically reduced. The simplicity and modularity of pillaring low-budget and environmentally friendly clays, combined with industrially capable performance with respect to thermal stability, high dynamic CO2 adsorption selectivity, and energy-efficient restoration renders MOPS-7 a highly attractive CO2 adsorbent.

Keywords

• physisorption
• MOPS
• separation
• selectivity
• dynamic breakthrough
• CO2