Infiltration of precursors into a porous alumina support for ZIF-8 membrane synthesis

A new synthesis method was developed to synthesize ZIF-8 membrane by infiltrating precursors into a porous alumina support as a seed-and-nutrient layer, and subsequent solvothermal synthesis. A precursor layer with a thickness of about 10 μm was formed inside the porous alumina support and the ZIF-8 membrane grew from both the seeds embedded in the precursor layer and the synthesis solution under solvothermal synthesis conditions. The effects of the solvothermal synthesis temperature and time were investigated, and a continuous and stable ZIF-8 membrane was prepared at 120 °C for 8 h. Gas permeation tests indicated the membrane synthesized at 120 °C for 8 h was continuous and compact, and had H2/N2 ideal selectivity of 5.7 with a H2 permeance of 1.7 × 10−7 mol m−2 s−1 Pa−1.

Graphical abstractA seed-and-nutrient layer was formed by infiltration of precursors into pores of alumina support to grow ZIF-8 membrane under solvothermal synthesis.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Infiltration of precursors into pores of alumina support as a seeding layer. ► Growth of ZIF-8 membrane from infiltrated precursors and synthesis solution. ► Continuous and compact ZIF-8 membrane showing H2/N2 ideal selectivity of 5.7.