Improved pore connectivity by the reduction of cobalt oxide silica membranes

•He permeance was constant for all He/CO2 mixtures under non-reduced conditions.•Anomalous H2 transport was observed under reduced conditions.•H2 permeance increased 170% from single H2 gas to H2/Ar gas mixtures.•H2 slowly reacted with dense Co3O4 in silica thus forming a porous CoO region.•Higher H2 permeance due to pore connectivity in the porous CoO region.