Synthesis of 5‐hydroxymethylfurfural from glucose over carbon‐based acid–base bifunctional catalyst

Abstract

Carbon‐based acid–base bifunctional catalyst was synthesized by the functionalization of activated carbon (AC) with 3‐mercaptopropyl trimethoxysilane, 3‐aminopropyl trimethoxysilane, and H2SO4 via sulfhydrylation, ammonifiation, and sulfonation successively. The as‐prepared catalyst of NH2‐AC‐SO3H was characterized by infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis and Brunauer–Emmet–Teller specific area analysis, and it was further used for producing fuel precursor 5‐hydroxymethylfurfural (5‐HMF) from glucose. The influences of the catalyst type, ratio of acid–base groups, catalyst amount, reaction temperature, and reaction time were investigated. It was found that NH2‐AC‐SO3H revealed excellent activity, and the yield of 5‐HMF reached 71.8% under the optimized reaction conditions with a 1.3:1 mass ratio of NH2‐AC‐SO3H to glucose at 140°C for 6 h in γ‐valerolactone. The reusability of NH2‐AC‐SO3H was also performed, and only slight decreases in the conversion of glucose and the yield of 5‐HMF were observed, still giving 65.3% yield of 5‐HMF after 4 runs.

Highly Efficient One-Pot Conversion of Glucose to 5-Hydroxymethylfurfural over Acid–Base Bifunctional MCM-41 Mesoporous Silica under Mild Aqueous Conditions

“…Particular efforts are being made to develop environmentally friendly heterogeneous catalysts instead of homogeneous ones because of the ease of their convenient separation and recycling procedures for the former. , In relation to the heterogeneous catalyst, more efforts have been dedicated to immobilize both acidic and basic sites on a single support. Until now, a wide range of support materials such as halloysite nanotubes, metal–organic frameworks, − zirconia, mesoporous silicas, graphene oxide, activated carbon, and porous nitrogen-doped carbon have been widely employed for preparing acid–base bifunctional catalysts. While these reports have greatly promoted the conversion of glucose to HMF, most of them suffer from a low yield of HMF, the consumption of ionic liquids and/or organic solvents or biphasic systems, and the use of hazardous metals.…”