초록 |
Algal biomass is regarded as a next-generation biomass owing to its rapid growth, inedibility, and lignin-free structure. Alginate, the major constituent of macroalgae, was hydrolyzed into uronic acids over sulfonated glucose-derived carbon catalysts using water as a green solvent under mild temperature conditions. The catalytic activity was compared with that of other conventional mineral acid and commercial solid acid catalysts such as sulfuric acid, carbon black, activated carbon, Amberlyst-15, and zeolites. The sulfonic group is an active site in the catalysis of the hydrolysis of alginate, and phenolic hydroxyl, whereas carboxylic groups on the carbon surface showed negligible effects on the hydrolysis reactions. The catalytic activity of the sulfonated carbon is higher than that of other commercial acid catalysts used in this work. The high activity of sulfonated glucose-derived carbon catalyst can be attributed to its high local acid density and carbohydrate-pi interaction between alginate and the catalyst. Uronic acids were further repolymerized into humins or epimerized into other uronic acids, which led to the decrease in the yield of target uronic acids. |