Saccharification of cellulose using biomass-derived activated carbon-based solid acid catalysts

Abstract

We prepared activated carbon-based solid acid catalysts derived from coconut shells via chemical activation with phosphoric acid under air and subsequent sulfonation. Their catalytic activities were evaluated in the saccharification of cellulose, and the parameters required for the activation and sulfonation processes were investigated. A catalyst activating temperature of 400 °C was found to be optimal, and the catalyst treated with chlorosulfuric acid exhibited a similar monosaccharide yield to that treated with fuming sulfuric acid. The prepared catalysts were characterized by various analytical techniques. The catalysts exhibited high specific surface areas and micropore volumes but low external specific surface areas. The catalysts had high contents of acidic functional groups when low activating temperatures were employed. For these catalysts, the surface chemical structure had a more dominant effect on the catalytic activity than that caused by the porous texture, while high acidic group contents led to high catalytic activities.