Synthesis of Sulfonated Carbon from Discarded Masks for Effective Production of 5-Hydroxymethylfurfural

Abstract

5−hydroxymethylfurfural (HMF), as one of the top ten important platform chemicals, can be used to produce 2,5−furandicarboxylic acid (FDCA), 2,5−dimethyl furan (DMF), levulinic acid, and other chemicals. An environmentally friendly system for the synthesis of sulfonated carbon materials from discarded masks has been proposed. A series of mask−based solid acid catalysts (bMC−SO3H) were prepared by a simple two−step process. Mechanochemical pretreatment (ball milling) of waste mask and sulfonated group precursor, followed by thermal carbonization under nitrogen gas, were used to synthesize sulfonated porous carbon. The total acid amount of the prepared bMC−SO3H was measured by the Boehm method, which exhibited 1.2–5.3 mmol/g. The addition of the sulfonated group precursor in the mechanochemical treatment (ball milling) process caused intense structure fragmentation of the discarded masks. These sulfonated porous carbons (bMC(600)−SO3H) as solid acid catalysts achieved fructose conversion of 100% and HMF yield of 82.1% after 120 min at 95 °C in 1−butyl−3−methylimidazolium chloride. The bMC−SO3H could be reused five times, during which both the HMF yield and fructose conversion were stable. This work provides a strategy for the synthesis of sulfonated carbon from discarded masks and efficient catalyzed fructose upgrading to HMF.

Towards Photothermal Acid Catalysts Using Eco-Sustainable Sulfonated Carbon Nanoparticles—Part I: Synthesis, Characterization and Catalytic Activity towards Fischer Esterification

“…The content of oxygenated (phenolic, lactonic and carboxylic acid groups) in the catalyst was determined by acid-base potentiometric titration using the standardized Boehm method [50,51]. The Boehm titration is based on the principle that the oxygenated groups present in the carbon surface have different acidity and can be neutralized by bases of different levels of alkalinity.…”

Structure and Catalytic Performance of Carbon-Based Solid Acids from Biomass Activated by ZnCl2

“…Specifically, the S 2p diffraction peak at 167.9 eV is attributed to the -SO 3 H sulfonic acid group in the catalyst. This suggests that the sulfur within the catalyst predominantly exists in the form of -SO 3 H, while the peak at 169.5 eV is ascribed to sulfate [36]. The deconvolution of the C 1s peak uncovers the presence of aromatic carbon (C=C, 284.6 eV), hydroxyl (-C=O, 286.2 eV), carboxylic acid carbon (-COOH, 288.6 eV), and hemiacetal or carboxylic acid carbon (-C=O, 286.5-287.5 eV).…”