Preparation of ZrC@Al₂O₃@Carbon composite aerogel with excellent high temperature thermal insulation performance

The ZrC@Al₂O₃@carbon composite aerogels are obtained from low-cost inorganic salt of zirconium and aluminum as raw materials through sol–gel route and carbothermal reduction process. The effects of reactant molar ratios and heat-treatment time on physicochemical properties of ZrC@Al₂O₃@carbon composite aerogels are investigated. The results show that the compressive strength of ZrC@Al₂O₃@carbon composite aerogel is as high as 1.31 MPa. The specific surface area of sample is as high as 650.4 m² g⁻¹, which is beneficial for its application of thermal insulation and catalyst supporting at elevated temperatures. After heat-treated at 1500 °C for 5 h, the thermal conductivity of carbon fiber mat reinforced composite aerogel is as low as 0.048 W m⁻¹ K⁻¹ (25 °C).