MF@TG-S highly selective catalytic conversion of agricultural waste straw into formic acid: Influencing factors, material characterization, and conversion mechanism

Agricultural straw waste is a major biomass waste resource. Efficient and highly selective conversion to platform chemicals is essential for making it a useful resource. However, traditional catalytic systems often exhibit non-selective C-C bond cleavage, which can reduce the yield of the desired products. In this study, a multifunctional composite catalyst (MF@TG-S) was developed to overcome this bottleneck. By immobilizing MIL-101(Fe) clusters on sulfonated 3D graphene, we fabricated a composite catalyst that combines Lewis acid, Brønsted acid, and hydrogen-bonding sites. This architecture allows for the selective cleavage of the C 2 -C 3 bond in glucose derivatives, rerouting it to form formic acid (FA). The optimized catalyst exhibited remarkable performance, achieving 99.70% cellulose conversion, a 76.49% FA yield, and an FA/CO 2 molar ratio of 4.13, which is nearly four times higher than that of conventional unfunctionalized solid acid catalysts. The degradation mechanism indicates that the multiple catalytic sites of the catalyst cooperatively guided the cleavage of the C 2 -C 3 bond of glucose, and then it was highly selectively converted into FA through fructose and 5-HMF. This study provides insights into the selective activation of biomass C–C bonds while laying out a technically viable route for the efficient production of high-value chemicals from lignocellulosic feedstocks. • MF@TG-S catalyst converts straw cellulose to formic acid with 76.49% yield. • Synergistic dual-acid sites enable selective C 2 -C 3 bond cleavage of glucose. • The FA/CO 2 ratio reached 4.13, four times higher than traditional systems. • Sulfonated graphene anchors Fe clusters to prevent leaching.