This study described a bifunctional catalyst consisted of iron nanoparticles (NPs) loaded in carbon decorated with nitrogen-sulfur heteroatoms (FeNC@S) for the oxidation-dehydration of fructose to 2,5-furandi-carboxylic acid (FDCA) or furan-2,5-dimethylcarboxylate (FDMC) via intermediate 2,5-diformyl-furan (DFF) with air as oxidant by two-step, which was manufactured by pyrolyzing a mixture of Fe-thiourea-chitosan. The synthesized FeNC@S catalyst exhibited outstanding activity and recyclability. More than 93% FDCA or FDMC was obtained. The characterization of the catalyst indicated that the modification of thiourea strongly promoted the dispersion of the FeO_x nanoparticles and specific surface. FeNC@S was characterized by abundant sulfonic acid groups, which provided sufficient acid sites for the fructose dehydration. The N-modification improved the activity of FeO_x for the 5-hydroxymethylfurfural oxidation via adjusting the electronic cloud distribution of FeO_x, increasing surface lattice oxygen ratio and oxygen mobility. And the mechanism study indicated the lattice oxygen activity was improved via weakening Fe-O bond strength. Further, this protocol provided an alternative idea for the efficient preparation of FDCA and FDMC from fructose.

该研究描述了一种双功能催化剂，该催化剂由负载在碳中的铁纳米颗粒 (NPs) 组成，碳上装饰有氮硫杂原子 (FeNC@S)，用于将果糖氧化脱水为 2,5-呋喃二羧酸 (FDCA) 或呋喃-2 ,5-二甲基羧酸盐 (FDMC) 通过中间体 2,5-二甲酰基-呋喃 (DFF) 与空气作为氧化剂通过两步法制备，它是通过热解 Fe-硫脲-壳聚糖的混合物制备的。合成的 FeNC@S 催化剂表现出优异的活性和可回收性。获得了超过 93% 的 FDCA 或 FDMC。催化剂的表征表明硫脲的改性强烈促进了FeO _{x的分散。}纳米颗粒和比表面。FeNC@S具有丰富的磺酸基团，为果糖脱水提供了足够的酸位点。N-修饰通过调节FeO _x的电子云分布、增加表面晶格氧比和氧迁移率来提高FeO _x对5-羟甲基糠醛氧化的活性。机理研究表明，通过削弱Fe-O键强度提高了晶格氧活性。此外，该协议为从果糖中高效制备 FDCA 和 FDMC 提供了另一种思路。