Resorcinol–formaldehyde (RF) aerogels were synthesized by polymerization and, then, were carbonized using a novel induction heated fluidized bed reactor (IHFBR). The obtained carbon aerogels were activated using CO2 while the effects of activation time ξ and CO2 concentration γ on the structural properties of carbon aerogels were examined. It is shown that activation by CO2 can be easily achieved using IHFBR while ξ and γ can affect the final structural properties of carbon aerogels. Large ξ or γ results in the loss of narrow and homogeneous distribution of mesopores while low γ solely changes the micropores superficially. Accordingly, possible mechanisms for changes in the structural properties of carbon aerogels were proposed. Using IHFBR can markedly reduce the activation time (from hours to minutes) by furnishing enhanced heat and mass transfer while facilitating the scale up process.