铈改性Ru/HAP催化果糖一步法制备2,5-呋喃二甲酸

采用浸渍法制备稀土元素铈（Ce）改性的Ru/HAP催化剂Ce-Ru/HAP，以实现果糖一步法制备2，5-呋喃二甲酸（2，5-FDCA）。采用XRD、TEM、NH₃-TPD和XPS表征手段对催化剂的理化性质进行分析。结果表明，Ce很好地高度分散到载体HAP上，且并未对HAP的结构造成影响；Ce主要以Ce³⁺和Ce⁴⁺形式存在，前者的存在使催化剂表面产生大量氧空穴，同时两者之间的电子转移有利于氧空穴形成，提高储氧能力，提高催化剂的表面催化活性；催化剂具有丰富的弱酸位，能够抑制反应过程中副反应的发生。优化反应条件后，催化剂Ce（8%，质量分数）-Ru/HAP在温度160℃和氧气压力2 MPa的反应条件下，反应4 h时2，5-呋喃二甲酸的产率为34.2%。因此，Ce的引入能够提高传统贵金属复合型催化剂的催化活性，同时也为果糖一步制备2，5-FDCA提供新思路。

One step synthesis of 2,5-furandicarboxylic acid from fructose catalyzed by Ce modified Ru/HAP

A series of Ce-modified Ru/HAP catalysts with different loadings were prepared by impregnation method, which were applied to the one-step preparation of 2,5-furandicarboxylic acid with fructose. The catalysts were characterized by XRD, TEM, NH₃-TPD and XPS. The results showed that Ce was highly dispersed on the HAP, and the addition of Ce affected little on the structure of HAP. Ce mainly exists in the form of Ce³⁺ and Ce⁴⁺. The presence of the Ce³⁺ makes a large amount of oxygen holes on the surface of the catalyst, and the electron transfer between Ce³⁺ and Ce⁴⁺ is conducive to the formation of oxygen holes, improves the oxygen storage capacity and the surface catalytic activity. The catalyst is rich in weak acid sites, which inhibits the side reactions. Among the catalysts evaluated, the sample of Ce (8%, mass ratio) -Ru/HAP showed satisfied performance with the 2,5-FDCA yield of 34.2% at 160℃ for 4 h reaction under a pressure of 2 MPa and a catalyst dosage of 0.1 g. Therefore, the introduction of Ce has greatly improved the catalytic activity of traditional precious metal composite catalysts, and also provided new ideas for the one-step preparation of fructose 2,5-FDCA.