TY - JOUR

T1 - Highly hydrogen-permselective zeolitic imidazolate framework ZIF-8 membranes prepared on coarse and macroporous tubes through repeated synthesis

AU - Zhu, Yaqiong

AU - Liu, Qian

AU - Caro, Jürgen

AU - Huang, Aisheng

PY - 2015/5/26

Y1 - 2015/5/26

N2 - Highly hydrogen-permselective zeolitic imidazolate framework ZIF-8 membranes are prepared on coarse and macroporous Al2O3 tubes through a repeated synthesis strategy for the separation of H2/CO2, H2/CH4, and H2/C3H8 mixtures. Since the amino-groups of 3-aminopropyltriethoxysilane (APTES) can coordinate to the free Zn2+ centers and thus bind the growing nano-crystals directly, the nucleation and growth of well intergrown ZIF-8 membranes could be promoted through a repeated synthesis of the ZIF-8 layer on APTES-modified macroporous Al2O3 tubes. The SEM and XRD characterizations indicate that a dense and phase-pure ZIF-8 membrane with a thickness of about 25.0 μm can be formed on the alumina tubes by microwave synthesis at 105 °C for 3 h, and no cracks, pinholes or other defects were observed in the membrane layer. The ZIF-8 membranes were evaluated in single gas permeation and mixed gas separation. Attributed to the preferential adsorption affinity and capacity as well as a highly porous structure with nano-sized channels, the ZIF-8 membrane displays a high hydrogen permselectivity. For the separation of equimolar H2/CO2, H2/CH4, H2/C3H8 mixtures at 100 °C and 2 bar, the mixture separation factors of H2/CO2, H2/CH4, and H2/C3H8 are 5.6, 44.0, 328.6, with a H2 permeance of about 1.1 × 10-7 mol m-2 s-1 Pa-1, which is promising for potential applications in hydrogen purification and separation.

AB - Highly hydrogen-permselective zeolitic imidazolate framework ZIF-8 membranes are prepared on coarse and macroporous Al2O3 tubes through a repeated synthesis strategy for the separation of H2/CO2, H2/CH4, and H2/C3H8 mixtures. Since the amino-groups of 3-aminopropyltriethoxysilane (APTES) can coordinate to the free Zn2+ centers and thus bind the growing nano-crystals directly, the nucleation and growth of well intergrown ZIF-8 membranes could be promoted through a repeated synthesis of the ZIF-8 layer on APTES-modified macroporous Al2O3 tubes. The SEM and XRD characterizations indicate that a dense and phase-pure ZIF-8 membrane with a thickness of about 25.0 μm can be formed on the alumina tubes by microwave synthesis at 105 °C for 3 h, and no cracks, pinholes or other defects were observed in the membrane layer. The ZIF-8 membranes were evaluated in single gas permeation and mixed gas separation. Attributed to the preferential adsorption affinity and capacity as well as a highly porous structure with nano-sized channels, the ZIF-8 membrane displays a high hydrogen permselectivity. For the separation of equimolar H2/CO2, H2/CH4, H2/C3H8 mixtures at 100 °C and 2 bar, the mixture separation factors of H2/CO2, H2/CH4, and H2/C3H8 are 5.6, 44.0, 328.6, with a H2 permeance of about 1.1 × 10-7 mol m-2 s-1 Pa-1, which is promising for potential applications in hydrogen purification and separation.

KW - Chemical modification

KW - Hydrogen separation

KW - Metal-organic frameworks (MOFs)

KW - Microwave synthesis

KW - ZIF-8 membranes

UR - http://www.scopus.com/inward/record.url?scp=84926013382&partnerID=8YFLogxK

U2 - 10.1016/j.seppur.2015.03.020

DO - 10.1016/j.seppur.2015.03.020

M3 - Article

AN - SCOPUS:84926013382

VL - 146

SP - 68

EP - 74

JO - Separation and Purification Technology

JF - Separation and Purification Technology

SN - 1383-5866

ER -