1、研究论文 Article *E-mail:;Tel.:13172092043 Received December 1,2022;published February 24,2023.Supporting information for this article is available free of charge via the Internet at http:/sioc-.Project supported by the National Natural Science Foundation of China(51976225,52236010).国家自然科学基金(51976225,52
2、236010)资助.Acta Chim.Sinica 2023,81,239245 2023 Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences http:/sioc- 239 化 学 学 报 化 学 学 报 ACTA CHIMICA SINICA 原位合成氮掺杂石墨烯负载钯纳米颗粒用于催化香兰素 高选择性加氢反应 徐斌a,b 韦秀芝b,d 孙江敏a,b 刘建国*,c 马隆龙*,c,d(a中国科学技术大学 能源科学与技术学院 合肥 230026)(b中国科学院广州能源研究所 可再生能源重点实验室 广州 5106
3、40)(c东南大学 能源与环境学院 南京 210096)(d中国科学技术大学 工程科学学院 合肥 230026)摘要摘要 通过原位合成法制备了氮掺杂石墨烯负载钯纳米颗粒催化剂 PdN/C-2,用于催化香兰素选择性加氢反应.采用 X 射线衍射(XRD)、扫描电子显微镜(SEM)、X 射线光电子能谱(XPS)等方法对 PdN/C-2 催化剂进行结构与性能的表征,分析表明石墨烯层在活性钯纳米颗粒表面起到了保护作用,提高了催化剂在反应条件下的稳定性,在五次循环回收实验后催化剂仍保持很高的反应活性.通过对石墨烯掺杂氮原子引入了催化反应的化学活性中心和金属纳米颗粒沉积的锚定中心,从而使石墨烯在加氢催化反应
4、中的性能得到进一步提高.并且通过对溶剂的调控实现了香兰素分别高选择性生成香草醇和对甲基愈创木酚,在优化的反应条件下,香草醇和对甲基愈创木酚的产率分别为 89%和 99%.关键词关键词 香兰素;香草醇;对甲基愈创木酚;均相催化剂;选择性加氢 In-situIn-situ Synthesis of Nitrogen-doped Graphene Layer Encapsulated Palladium Synthesis of Nitrogen-doped Graphene Layer Encapsulated Palladium Nanoparticles for Highly Selectiv
5、e Hydrogenation of Vanillin Nanoparticles for Highly Selective Hydrogenation of Vanillin Xu,Bina,b Wei,Xiuzhib,d Sun,Jiangmina,b Liu,Jianguo*,c Ma,Longlong*,c,d(a School of Energy Science and Engineering,University of Science and Technology of China,Hefei 230026)(b CAS Key Laboratory of Renewable En
6、ergy,Guangzhou Institute of Energy Conversion,Guangzhou 510640)(c School of Energy and Environment,Southeast University,Nanjing 210096)(d School of Engineering Science,University of Science and Technology of China,Hefei 230026)Abstract As the only natural and sustainable carbon source,biomass shows
7、great potential in solving current environmental and energy problems and creating a carbon-neutral society.Selective hydrogenation is a kind of important reaction.Various unsaturated functional groups in biomass are typical targets of selective hydrogenation.Therefore,selectivity is the key index to
8、 measure the efficiency of the hydrogenation reaction.Vanillin is an important platform compound in biomass conversion.In recent years,selective hydrogenation of vanillin to biofuels and other high-value-added chemicals has received widespread attention.Because vanillin has different reducible funct
9、ional groups(aldehyde group,methoxy group,and hydroxyl group),it is very important to control the selectivity of vanillin hydrogenation.Vanillyl alcohol has long-lasting sweetness and nutty aromas and is used in the food and perfume industries.2-Methoxy-4-methylphenol(MMP)is also an important biofue
10、l.Therefore,selective hydrogenation of vanillin to vanillyl alcohol or MMP is an important synthesis route.Here,we propose a strategy to introduce the chemical active center of catalytic reaction and the anchoring center of metal nanoparticle deposition by doping nitrogen atoms of graphene,which mak
11、es the application of graphene in hydrogenation catalysis obtain better per-formance.In this work,we report a simple method for in-situ synthesis of nitrogen-doped graphene-supported palladium nanoparticles PdN/C-2 catalyst and its application in selective hydrogenation of the CO bond.The prepared c
12、atalyst has good catalytic activity and product selectivity for the hydrogenation of vanillin and has the advantages of simple preparation,high activity and stable performance.It is easy to be separated from organic reaction conditions and can be reused many times.Under relatively mild reaction cond
13、itions,PdN/C-2 catalyzed the complete conversion of vanillin to vanillyl alcohol and MMP,and the yields were 89%and 99%,respectively.It is worth noting that through the regulation of solvents,we achieved highly selective hydrogenation of vanillin to vanillyl alcohol and MMP,respectively.Keywords van
14、illin;vanillyl alcohol;2-methoxy-4-methylphenol;homogeneous catalyst;selective hydrogenation DOI:10.6023/A22120481 化化 学学 学学 报报 研究论文 240 http:/sioc- 2023 Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences Acta Chim.Sinica 2023,81,239245 1 引言 生物质是地球上储量最大的碳质可再生资源,因其含有多种含氧官能团,可转化为各种高附加值
15、化学品1.选择性加氢是实现生物质及其衍生物转化的常用策略,由于大多数生物质及其衍生物含有多种可还原的官能团,所以控制加氢反应的活性和选择性是一个巨大的挑战2.香兰素由木质素生物质热化学解聚或生物解聚而来,是一种很有前景的生物质平台化合物,具有催化加氢生成高附加值化合物和生物燃料的巨大潜力3-4.香兰素的选择性加氢主要包括对醛基的加氢还原和加氢脱氧.对醛基的加氢还原可以得到香草醇,香草醇具有与香兰素相似的甜味和坚果香味,且更加持久和稳定,被广泛应用于食品、医药和香水行业5;由于香兰素含氧量高,作为生物燃料存在能量密度低、燃烧不稳定、腐蚀过度等缺点,对醛基进行加氢脱氧反应生成对甲基愈创木酚(MMP
16、)可以有效降低含氧量从而提高生物燃油的品质.然而香兰素上的多种官能团导致加氢过程中存在不可控的副反应,因此香兰素的选择性转化是具有挑战性的6.对于香兰素加氢反应而言,反应难点在于加氢产物的可控性转化.同一催化剂通常只能实现一种产物的完全转化或两种产物的部分转化.例如 Duan 等7用 Ni-Co-P/羟磷灰石(HAP)催化剂催化香兰素加氢脱氧反应,在 200 下反应 3 h 生成 MMP.Alijani 等8采用 Pd-活性碳催化剂对香兰素进行加氢反应,对香草醇的选择性低于 80%.所以同一催化剂通过调控反应条件实现香草醇和 MMP 两种产物的完全转化是非常有意义的.关于催化醛类的还原,已报道了 Ni9、Cu10、Co11、Pt12、Au13、Ru14、Ir15、Ru16和 Pd17-20等负载型金属非均相催化剂.在这些过渡金属催化剂中,我们发现负载 Pd 纳米颗粒的催化剂在醛基加氢还原中具有许多优势.Pd 基催化剂在温和的工艺条件下表现出加氢高活性,并且在溶剂介质中重复使用时也能保持其性能.但是在香兰素加氢反应中,Pd 催化剂通常不能做到两种产物的可控性转化,这是因为 Pd 的过度
