Isomerization of hexoses from enzymatic hydrolysate of poplar sawdust using low leaching K2MgSiO4 catalysts for one-pot synthesis of HMF

Abstract

A cost-effective K_1.5Mg/SiO₂ catalyst with a K₂MgSiO₄ component was employed to help transfer several hexoses into hydroxylmethylfurfural (HMF) in a biphasic water/butanol system. The solid catalysts with rod-like structures and moderate base sites could promote the aldose–ketose isomerization of glucose and have potential for the synthesis of lactic acid via a retro-aldol condensation. In the presence of sulfonated titania/mordenite solid acid, the K_1.5Mg/SiO₂ catalyst presented heat-stability and prolonged activity in the one-pot conversion of glucose to HMF, leading to an optimal yield of 62.2%. The one-pot catalysis of saccharides from the enzymatic hydrolysate of poplar sawdust achieved a high HMF yield of 56.9% at a glucose conversion of 91.6%.