A highly active willow-derived sulfonated carbon material with macroporous structure for production of glucose

A novel willow-based solid acid catalyst was successfully prepared through sulfonation of pencil refill. This solid acid catalyst bearing SO₃H and COOH groups shows macroporous structure, which is more suitable for conversion of cellulose into glucose, resulting in 78.0 % conversion and 65.0 % glucose yield at 160 °C for 8 h reaction time. Its activity was comparable to other carbon sulfonated acid catalysts made from pure starch or glucose, respectively, due to its acidic property as well as macroporous structure. Additionally, the willow-derived catalyst could be repeatedly employed for at least three cycles while retaining around 89 % of its original activity, exhibiting excellent operational stability. These results clearly show that use of this willow-derived catalyst is an economic, ecofriendly, and promising approach for production of glucose from cellulose and may open wide applications.