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

Abstract

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.

Cellulose Functionalization Using N-Heterocyclic-Based Leaving Group Chemistry

“…The hydrogen bond network and molecular packing impart high crystallinity in cellulosic materials, making them chemically less penetrable. Therefore, cellulose functionalization requires preactivation, either with the help of reactive chemicals (surface-modifying chemicals, such as epoxides, azides, and amines) [ 5 , 6 , 7 , 8 ] or by enforcing other energy-consuming processes (such as photoactivation, hydrothermal, thermomechanical) [ 9 , 10 , 11 , 12 , 13 ]. Due to the availability of a wide range of reactive chemical auxiliaries for cellulose material processing, various commercial-grade cellulose forms have been discovered, including nitrocellulose, sulpho-cellulose, cellulose acetate, and cellulose phosphate.…”

Chitin Hydrolysis Using Zeolites in Lithium Bromide Molten Salt Hydrate

“…So far, different catalytic approaches to depolymerize cellulose into glucose and cello-oligosaccharides have been developed by catalysis, mechanocatalysis, and enzymolysis. − Among various solid acid catalysts, zeolites are an important category owing to their low-cost, stability, and customizable architectures. − The depolymerization of cellulose, a structural analogue of chitin, into glucose using silicalite-1-modified HY, HZSM-5, ,,, H-β, , H-mordenite, , H-faujasite, and SAPO-34 has been explored in recent years. Mu et al reported that the hydrolysis of cellulose is sensitive to the acid density of HZSM-5, featuring a decreasing trend with an increase of the Si/Al ratio .…”