Synthesis of a novel porous material comprising carbon/alumina composite aerogels monoliths with high compressive strength

Resorcinol-formaldehyde/alumina composite (RF/Al₂O₃) gels were initially prepared by using sol-gel techniques, and then dried to aerogels with supercritical fluid CO₂. After thermal treatment in argon atmosphere, RF/Al₂O₃ aerogels were successfully converted to monolithic carbon/alumina composite (C/Al₂O₃) aerogels. The samples were characterized by BET, SEM, TEM and XRD, and the compressive strengths were measured. The experimental results showed that the C/Al₂O₃ aerogels exhibited an interpenetrating framework with high mesoporosity. The as-synthesized C/Al₂O₃ aerogels consisted of spherical carbon particles and alumina (fibrous or columnar), which had high BET surface area (576-831 m²/g) and showed high compressive strength (5.4-9.1 MPa) and Young's modulus (286.95-476.71 MPa). These novel C/Al₂O₃ aerogels could possibly be used as thermal isolates, catalysts and adsorbents.