Role of Catalyst on the Formation of Resorcinol-Furfural Based Carbon Aerogels and Its Physical Properties

Abstract

Carbon aerogels (CAG) were synthesized by the pyrolysis of resorcinol-furfural based organic aerogels, derived from sol-gel polymerization of resorcinol and furfural using different catalysts followed by supercritical drying of as-prepared gels. Different catalysts viz. hydrochloric acid (HA), acetic acid (AcH) and hexamethylenetetramine (HMTA) of different concentrations were used for this purpose in order to study the role of different catalysts and the effect of R/C ratio (reactant to catalyst molar ratio) on the formation of organic gel monolith and their physical properties were investigated. Aerogels were thoroughly characterized by using CHN, FTIR, TG-DSC, XRD and SEM. A considerable reduction of gelation time and the formation of relatively denser organic gel were observed in the case of HMTA, which indicated the dual role (catalyst & cross-linking agent) of HMTA during the polymerization/polycondensation of resorcinol and furfural. Carbon aerogels obtained by using different catalysts showed BET surface area, average pore size, total pore volumes in the range of 438 -496 m 2 /g, 17.9 -22.4 Å and 0.20 -0.27 cm 3 /g, respectively. The SEM images and results revealed the presence of different morphologies of carbon aerogels, obtained by using different catalysts. The HMTA catalyzed samples were found to have highest surface area with particles in smaller in size and well interconnected 3D carbon network.

Characteristics of carbon aerogel at variation in pyrolysis conditions

“…The experiments data showed that properties of carbon aerogel were affected of many factors such as the catalyst concentration, the initial gel pH, the concentration of solids in the sol, the drying method and the conditions of pyrolysis and activation. Carbon aerogel was synthesized from resorcinol-furfural based organic aerogels in the study of Rejitha et al [4]. Carbon aerogels obtained by using different catalysts showed BET surface area, average pore size, total pore volumes in the range of 438-496 m 2 /g, 17.9-22.4 Å and 0.20-0.27 cm 3 /g, respectively.…”

Lithium-Catalyzed Carbon Aerogel and Its Possible Application in Energy Storage Materials

“…Examples of other non-metal catalysts are acetic acid, hydrochloric acid, nitric acid, and hexamethylenetetramine. [11][12][13] The quality determining factor of carbon aerogels is also pyrolysis, which converts organic aerogels into carbon aerogels. Generally pyrolysis is responsible for changing the specific surface area and conductivity of aerogels.…”