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Mechanism of Gas Separation through Amorphous Silicon Oxycarbide Membranes
Author(s) -
Prasad Ravi Mohan,
Jüttke Yvonne,
Richter Hannes,
Voigt Ingolf,
Riedel Ralf,
Gurlo Aleksander
Publication year - 2016
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201500380
Subject(s) - materials science , permeance , amorphous solid , microporous material , chemical engineering , membrane , physisorption , permeation , porosity , hydrogen , diffusion , gas separation , ceramic , argon , composite material , chemistry , crystallography , organic chemistry , adsorption , thermodynamics , biochemistry , physics , engineering
Polymer‐derived amorphous silicon oxycarbide (SiOC) ceramics are designed for hydrogen separation at high temperatures. To form amorphous SiOC top‐coating with the thickness of about 300 nm, tubular porous γ‐Al 2 O 3 /α‐Al 2 O 3 substrates with gradient porosity are threefold coated by vinyl‐functionalized polysiloxane and pyrolyzed at 700 °C under argon. N 2 ‐physisorption measurement confirms formation of microporous material with a specific surface area of about 400 m 2 g –1 . Single gas permeance characterization of the SiOC membrane at 300 °C reveals H 2 /CO 2 and H 2 /SF 6 ideal permselectivities of about 10 and 320, respectively. The experimental gas permeance data are modeled using solid‐state diffusion (for He and H 2 ) and gas translational diffusion (for CO 2 and SF 6 ) mechanisms.