Iron-Modified Acid Carbons for the Conversion of Fructose to 5-Hydroxymethylfurfural under Microwave Heating

Autor(es)

Machado, Leticia F. L. ; Andrade, Luana S. ; Mandelli, Dalmo ; Carvalho, Wagner A.

• Tipo de documento: Artigo Científico
• Fonte: ACS OMEGA; v. 9, n. 45, p. 14-pg., 2024-11-01.

Resumo

Carbons with Br & oslash;nsted acidic sites and iron oxide modifications were prepared through hydrothermal carbonization and glycerol pyrolysis in the presence of sulfuric acid, magnetite, and iron(III) nitrate. The solids were tested as catalysts in converting fructose to 5-hydroxymethylfurfural (5-HMF). Characterization techniques revealed a uniform presence of 4.89 mmol g-1 total acidic groups, including up to 1.87 mmol g-1 sulfonic and carboxylic groups. Combined with a reduced surface area, the Br & oslash;nsted and Lewis acidity enabled the conversion of 94% of fructose with selectivity values as high as 95% for 5-HMF in just 10 min at 140 degrees C, using microwave heating and dimethyl sulfoxide (DMSO) as the solvent. This performance was attributed to the selective heating of the catalyst surface by the microwave absorption capacity of the acidic groups and iron oxide, leading to the formation of "hot spots." The catalyst obtained by hydrothermal carbonization in the presence of Fe3O4, HCC-20% Fe3O4, demonstrated stability when reused for up to four consecutive cycles. A slight reduction in conversion and selectivity was observed after the first use, attributed to the presence of acid species not incorporated into the solid during the synthesis process. (AU)

• Processo FAPESP: 23/17516-1 - Produção de Adsorventes Seletivos Para a Remoção de Nutrientes de Efluentes de Tratamento de Esgotos na Perspectiva de Reuso como Biofertilizante
• Beneficiário: Wagner Alves Carvalho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 22/06708-4 - Síntese mediada por estrutura metalorgânica (MOFMS): catalisadores para oxidação de metano em produtos oxigenados
• Beneficiário: Luana dos Santos Andrade
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado