Nanostructured Carbon Xerogels by Super-Fast Carbonization

Traditional synthesis methods of highly porous carbon xerogels impose many limitations on production in large scale such as low heat and mass transfer and long processing time. In this study, for the first time, recorsinol–formaldehyde (RF) xerogels were carbonized by fast heating rates (σ) in a fluidized bed reactor. The specific surface area (Φ) and pore volume of carbon xerogels were examined in terms of particle size (≈ 100 and 297 μm), carbonization temperature (298–1273 K), and σ (5–50 K min–1). The temperature above which Φ decreases by increasing temperature was shifted to lower values for larger particles. Moreover, Φ and volume of micro- and mesopores increased by increasing σ. Possible mechanisms to interpret the effects of carbonization temperature and σ on physical properties of carbon xerogels were finally furnished. Carbonization time was found to be ≈25-times faster by fluidization while maintaining the quality of xerogels.