Mechanochemical Preparation of a H3PO4-Based Solid Catalyst for Heterogeneous Hydrolysis of Cellulose

Cellulose saccharification to produce glucose is considered as an important approach for application of biomass resources. Solid acids as catalysts for this purpose have attracted much attention with the advantages of environmental friendliness, easy separation of products, and recyclability. In this work, a new method was introduced to prepare a H3PO4-based solid acid catalyst by simply grinding with kaolinite. Characterizations of the prepared products based on a set of analytical methods as well as cellulose hydrolysis were investigated and optimized. Loading H3PO4 on kaolinite with a mass ratio of 20% was used as a high-stability green catalyst. Cellulose hydrolysis occurred on the prepared catalyst even at much mild conditions with a low temperature of 343 K, and a yield of glucose products at 6.85% was achieved at optimized conditions. A catalytic activity of 82% remained after three cycles of use. The possible hydrolysis of cellulose under very low temperature demonstrates a potential approach for promoting biomass conversion into useful materials.