Hydrogen selective nanoporous SiC membrane at high temperature

Ceramic membranes having nano sized pores have great potential for gas separation at high temperature due to their good thermal stability. Moreover, nanoporous silicon carbide membrane has potential application under hydrothermal condition at high temperature. In this research, nanoporous SiC membrane has been developed on the porous alumina plate using a chemical vapour technique. The average thickness of the SiC membrane is ranged from 1 μm to 10μm. SiC coated porous alumina possesses asymmetric pore size distribution. There are micropores originated from porous alumina substrate and nanopores derived from amorphous state of SiC membranes. Pore size distribution measurement shows that the sample contains 1-2 nm sized nano pores. The hydrogen permeability and selectivity toward nitrogen gas were measured using a single gas method. The produced SiC membranes showed hydrogen permeances in the range of 0.43x 10⁻⁶ ~1.7x10⁻⁶ mol/m2.s.Pa and selectivity for H2 gas is 3.09 ~ 117.5 toward N2 gas. The developed nanoporous hydrogen selective SiC membrane shows promise for the applications in hydrogen separation from water electrolysis at high temperature or steam reforming reaction of natural gas since SiC membrane is stable at hydrothermal condition.