Sulfonated Graphitic Carbon Catalyst Derived from Coffee Waste: A Sustainable Valorization Approach for Highly Efficient Production of 5-Hydroxymethylfurfural (5-HMF) from Fructose

Abstract

According to recent research, a sulfonated 2D graphitic carbon catalyst for the dehydration of fructose to the platform chemical 5-Hydroxymethylfurfural (5-HMF) can be made from used ground coffee. By carbonizing and activating at different temperatures, sulfonated graphitic carbon (SC) catalysts with varied chemical compositions and textural characteristics were obtained. The physical and chemical characteristics of the SC catalysts were assessed using XRD, Raman, SEM-EDX, HR-TEM, BET analysis, and XPS. Due to its microporous structure, SC-900 exhibited a high specific area and demonstrated selective and efficient production of 5-HMF from fructose. All in all, the surface acidity of catalysts was measured by NH3-TPD, and acid-base titration methods. The SC-900 catalyst, designed through carbonization at 900 ℃, achieved a fructose conversion rate of 100% and a 5-HMF yield of 97.91% without generating any by-products. This indicates the catalyst essentially produces 5-HMF under the specified optimal conditions (140 ℃, 90min) observed in this study. To determine the origins of the highly efficient and highly selective conversion of fructose to 5-HMF, the performance of the SC catalysts was systematically investigated vi-a-vis their physical and chemical properties. The development of microporous SC catalysts and their application as catalysts not only enhances the value of waste coffee but also provides an environmentally friendly approach for converting carbohydrates into 5-HMF.