Synthesis and crystal structure analysis of a novel microporous barium-containing silicate AES-20

Abstract A novel microporous barium-containing silicate AES-20 was successfully synthesized, and its crystal structure was determined based on the ab - initio structure analysis from powder X-ray diffraction data. AES-20 was composed of unique silicate layers having 8- and 5-rings and interlayer barium atoms pillaring the silicate layers. AES-20 was obtained through the hydrothermal synthesis in the presence of lithium cations, which were involved in AES-20 as extra-framework species. The 8-ring micropore in AES-20 is smaller than a nitrogen molecule but larger than a carbon dioxide molecule, suggesting the application to a size-selective adsorbent for carbon dioxide removal.