Selective oxidation of biomass platform molecule 5‐hydroxymethylfurfural (HMF) into valuable bio‐monomer 2,5‐furandicarboxylic acid (FDCA) is an important biorefinery process. In our work, the structure‐activity relationship of Au nanoparticles supported on the composite of hydrotalcite and activated carbon (HT‐AC) toward selective oxidation of HMF to FDCA without a base was studied with a focus on the influence of support property and Au particles size. The initial conversion rate of substrates and the intrinsic selectivity of products were investigated. Various physicochemical techniques including XRD, Raman, XPS, CO₂‐TPD and TEM were used to characterize the HT‐AC supports and the Au/HT‐AC catalysts. Synergistic support effect was observed when HT and AC were combined to show the features of both basic sites and oxygen‐containing functional groups attached to the catalyst surface, which eventually promoted the adsorption of HMF and the formation of FDCA. The Au NPs were found in metallic state and highly dispersed with a mean size of 2.5 nm, which was favored to efficiently convert HMF to FDCA. It was disclosed that both the support effect and Au size effect could promote FDCA production through accelerating the conversion rate of HMF and HMFCA, and the rate‐determining step was determined in HMFCA transformation.

中文翻译：

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载体性质和粒径对5-羟基甲基糠醛的金催化无碱好氧氧化的影响

生物质平台分子5-羟甲基糠醛（HMF）选择性氧化为有价值的生物单体2,5-呋喃二甲酸（FDCA）是重要的生物精炼过程。在我们的工作中，研究了水滑石与活性炭（HT-AC）复合材料上负载的Au纳米颗粒对HMF选择性氧化成无碱的FDCA的结构-活性关系，重点研究了载体性质和Au颗粒的影响尺寸。研究了底物的初始转化率和产物的固有选择性。各种物理化学技术，包括XRD，拉曼，XPS，CO ₂TPD和TEM用于表征HT-AC载体和Au / HT-AC催化剂。当HT和AC结合使用时，观察到协同支持作用，显示出碱性位点和附着在催化剂表面的含氧官能团的特征，最终促进了HMF的吸附和FDCA的形成。发现金纳米颗粒处于金属状态并高度分散，平均粒径为2.5 nm，这有助于将HMF有效地转化为FDCA。公开了通过促进HMF和HMFCA的转化率，支持效应和Au尺寸效应都可以促进FDCA的产生，并且在HMFCA转化中确定了速率确定步骤。