Mesoporous Activated Carbon Structure Originated from Cross-Linking Hydroxyethyl Cellulose Precursor by Carboxylic Acids

Mesoporous matrixes of activated carbon (AC) are normally synthesized using the hard or soft template method. This work explores a template-free method to synthesize a mesoporous AC matrix through creating interchain bonding in its precursor. Hydroxyethyl cellulose (HEC) was adopted as a precursor, and its polymer chains were covalently cross-linked by the esterification reaction. Four types of organic carboxylic acids were used to examine the effect of esterification cross-linking on the formation of a mesoporous structure primarily through the course of pyrolysis. The BET surface analysis of the resulting ACs reveals an explicit correlation between the number of carboxylic acid groups on a benzene ring and the mesoporous structures of a synthesized AC. Moreover, it is also found that an optimal cross-linking degree for attaining the maximum volume fraction of mesopores exists with respect to each type of the cross-linker used. An attempt was made to understand how a cross-linked HEC is converted to a porous structure of an AC. The mesoporous structures of the ACs synthesized were also assessed by their capability of stripping H2S from a gas stream.