Zirconia-based alumina compound aerogels with enhanced mesopore structure

In this study, zirconia-based alumina compound aerogels with enhanced thermal stability were synthesized using a sol-gel process, followed by ambient-pressure drying (APD). Phase-separation control during alcogel synthesis was a critical aspect of APD because of the different sol-gel reaction rates of two-component aerogels. In the present study, we effectively addressed this issue by controlling the sol-gel reaction parameters to obtain a zirconia-based alumina aerogel with atomically bonded Zr-O-Al. This atomic bonding played an important role in maintaining the pore structure of the zirconia aerogels during APD. The compound aerogels inhibited pore structure collapse and increased the specific surface area. In addition, their thermal stability was better than that of pure zirconia aerogels. The textural and physical properties also improved due to the formation of a compound with alumina. Considering these results and the enhanced pore structure of these compound aerogels, they are potentially useful for high-temperature thermal insulation.