An oriented, siliceous deca-dodecasil 3R (DDR) zeolite film for effective carbon capture: insight into its hydrophobic effect. Issue 22 (24th May 2017)

• Record Type: Journal Article
• Authors: Kim, Eunjoo; Hong, Sungwon; Jang, Eunhee; Lee, Jeong Hyeon; Kim, Jin Chul; Choi, Nakwon; Cho, Churl Hee; Nam, Jaewook; Kwak, Sang Kyu; Yip, Alex C. K.; Choi, Jungkyu
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 22(2017)
• Page Start: 11246
• Page End: 11254
• Publication Date: 2017-05-24
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta02462b
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : An oriented, hydrophobic membrane made of a decadodecasil 3 rhombohedral (DDR) zeolite (0.36 nm) could separate CO2 (0.33 nm) from larger N2 (0.364 nm) reliably. Abstract : An all-silica deca-dodecasil 3R (Si-DDR) zeolite with a pore size of 0.36 × 0.44 nm 2 is highly desirable for membrane-based separation of CO2 (0.33 nm) from N2 (0.364 nm), which is critical in the post-combustion carbon capture process, via molecular recognition of their slight size difference. For the first time, we acquired h 0 h -oriented, hydrophobic DDR zeolite films through the epitaxial growth of a DDR seed layer with a structure directing agent of methyltropinium iodide. The degree of the out-of-plane orientation and inter-growth was increased with the secondary growth time, while reducing the defects that provide non-selective pathways. The resulting DDR membrane showed a CO2 /N2 separation factor (SF) as high as 11.9 at 50 °C (a representative flue-gas temperature) under dry conditions. More desirably, it could achieve a much enhanced CO2 /N2 SF of up to 15.9 at 50 °C in the presence of H2 O vapor (3 rd largest component in the flue-gas). The transport of the larger N2 molecule, plausibly its entering the pore mouth of DDR zeolites, was more inhibited by H2 O molecules adsorbed on the membrane surface; it appears that this surface resistance was due to the hydrophobicity of the highly siliceous DDR membrane and beneficial for improving CO2 /N2 SFs under wet conditions.