Synthesis of Carbide Compounds Derived from Colloidal Oxide and Carbohydrate

Abstract

Silicon carbide (SiC) and zirconium carbide (ZrC) powders were synthesized by the carbothermal reduction reaction of carbon and the corresponding metal oxide silica or zirconia respectively. The physical and chemical properties of the final products were studied according to the nature of precursors used: colloidal or micrometric powders for the oxides, sucrose, mannitol or sorbitol for the reducing agent. After mixing and freeze drying of these components, the powder was heated at temperatures ranging from 1300 and 1550°C under flowing argon to obtain the carbides. Depending on the nature of the precursors (colloidal or micrometric) an increase of more than one order in the magnitude of the surface area was observed. The highest surface area (300m²/g) was measured on a ZrC+C compound type elaborated from a colloidal precursor. The use of colloids in carbothermal reaction could be a route to control pore size in mesoporous carbides or supported porous carbon materials.