Inkjet Printing of Microporous Silica Gas Separation Membranes

Inkjet printing was applied to manufacture silica‐based gas separation membranes, which were coated on a pore‐graduated alumina substrate with a mesoporous γ‐alumina interlayer. A silica sol diluted by 1‐propanol was used to print the membrane layer followed by thermal treatment in a rapid thermal processing furnace. The membrane thickness was varied between 30 and 110 nm by conducting one, two, and three coating steps. In the latter case, H₂ permeance in the range of 2.0 × 10^?8–3.3 × 10^?8 mol/s·m²·Pa combined with H₂/CO₂ selectivities in the range of 15–25 were achieved, proving the concept that inorganic gas separation membranes can be successfully processed by inkjet printing.