▎ 摘　　要

Thermally reduced graphene oxide (TRGO) was functionalized using sulfuric acid, phosphoric acid, and 4-benzenediazonium sulfonate generated in situ to obtain solid acid graphene-based catalysts. The prepared samples were characterized using different techniques, i.e., elemental and textural analyses, microscope investigations, thermogravimetric analysis, XPS measurements, and acid-base titration. The obtained results revealed differences in the susceptibility of TRGO to functionalization with various modifying agents and in the chemical properties of the final carbon products. The catalytic performance of the graphene-based samples was further tested in the reaction of glycerol esterification performed with acetic acid at 110 degrees C using glycerol to acetic acid molar ratio of 1:6. The catalysts were found to be active in the tested process, however, satisfactory results were obtained only in the presence of TRGO modified with 4-benzenediazonium sulfonate (TRGO_BDS). This sample gave almost 100% conversion of glycerol just within 1 h of the reaction, along with a very high combined yield of di- and triacetins, i.e., the products of interest, of about 70%. The excellent activity of TRGO_BDS was ascribed to a high content of surface SO3H groups which were found to promote a high rate of reaction and the formation of higher acetins. The phosphate groups present on the surface of TRGO modified with phosphoric acid were also able to catalyze the process, however, their catalytic efficiency in the reaction was considerably lower than that of sulfonic groups.