The synthesis of furan-2,5-dicarboxylic acid via catalytic oxidation of 5-hydroxymethyl furfural is an important step for the production of bio-sourced polymers. We report on the activity of SiO₂-supported Au catalysts for this reaction. These catalysts reached 74% furan-2,5-dicarboxylic acid yield at 90 °C in 5 h when 5-hydroxymethyl furfural to Au molar ratio was 72. We also investigated the influence of the morphologies of the silica supports on the growth of Au nanoparticles under reaction conditions. Pronounced growth of Au nanoparticles occurred on Aerosil, SiO₂ with a disordered porosity and 50 nm average pore diameter: Au nanoparticles grew from 2.4 to 10.1 nm. However, by using ordered mesoporous supports, the growth of the gold nanoparticles was successfully minimized. Also the reaction conditions influenced the particle growth; for instance using HCO₃⁻ as a base led to more pronounced particle growth than using NaOH. Particle diffusion in solution, and subsequent coalescence and agglomeration was proposed to be the dominant particle growth mechanism. Our results show the importance of support morphology in mitigation of Au particle growth in liquid phase oxidation reactions.

通过5-羟甲基糠醛的催化氧化合成呋喃-2,5-二羧酸是生产生物来源聚合物的重要步骤。我们报道了该反应中SiO ₂负载的Au催化剂的活性。当5-羟甲基糠醛与金的摩尔比为72时，在90°C下5小时内，这些催化剂在5小时内达到呋喃-2,5-二羧酸的74％收率。我们还研究了二氧化硅载体的形貌对Au生长的影响在反应条件下的纳米颗粒。在Aerosil，SiO ₂上发生了金纳米颗粒的明显生长孔隙率无序且平均孔径为50 nm：Au纳米颗粒从2.4 nm增长到10.1 nm。然而，通过使用有序的介孔载体，金纳米颗粒的生长成功地最小化。反应条件也影响颗粒的生长。例如使用HCO ₃ ^-作为碱导致比使用NaOH更明显的颗粒生长。颗粒在溶液中的扩散以及随后的聚结和团聚被认为是主要的颗粒生长机理。我们的结果表明，载体形态对缓解液相氧化反应中金颗粒的生长非常重要。