Microenvironment engineering of nitrogen-doped hollow carbon spheres encapsulated with Pd catalysts for highly selective hydrodeoxygenation of biomass-derived vanillin in water  

用于生物质基香草醛水相高选择性加氢脱氧的氮掺杂中空碳球负载Pd催化剂的微环境设计和构筑

作　　者：Jun Wu Liqian Liu Xinyue Yan Gang Pan Jiahao Bai Chengbing Wang Fuwei Li Yong Li 吴君;刘立乾;严鑫悦;潘刚;白家豪;王成兵;李福伟;李永(陕西科技大学材料科学与工程学院,无机材料绿色制备与功能化陕西省重点实验室,陕西西安710021;中国科学院大学化学工程学院,北京100049)

机构地区：[1]School of Materials Science&Engineering,Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials,Shaanxi University of Science&Technology,Xi'an 710021,Shaanxi,China [2]School of Chemical Engineering,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Journal of Catalysis》2025年第4期267-284,共18页催化学报(英文)

基　　金：国家自然科学基金(21902094,22472177);陕西省自然科学基金(2023-JC-QN-0103);中国博士后面上基金(2020M683405);陕西省教育厅科研计划项目(23JK0344).

摘　　要：Development of efficient and stable metal catalysts for the selective aqueous phase hydrodeoxygenation(HDO)of biomass-derived oxygenates to value-added biofuels is highly desired.An innovative surface microenvironment modulation strategy was used to construct the nitrogen-doped hollow carbon sphere encapsulated with Pd(Pd@NHCS-X,X:600–800)nanoreactors for catalytic HDO of biomass-derived vanillin in water.The specific surface microenvironments of Pd@NHCS catalysts including the electronic property of active Pd centers and the surface wettability and porous structure of NHCS supports could be well-controlled by the calcination temperature of catalysts.Intrinsic kinetic evaluations demonstrated that the Pd@NHCS-600 catalyst presented a high turnover frequency of 337.77 h^(–1)and a low apparent activation energy of 18.63 kJ/mol.The excellent catalytic HDO performance was attributed to the unique surface microenvironment of Pd@NHCS catalyst based on structure-performance relationship analysis and DFT calculations.It revealed that pyridinic N species dominated the electronic property regulation of Pd sites through electronic metal-support interaction(EMSI)and produced numerous electron-rich active Pd centers,which not only intensified the dissociation and activation of H2 molecules,but also substantially improved the activation capability of vanillin via the enhanced adsorption of–C=O group.The fine hydrophilicity and abundant porous structure promoted the uniform dispersion of catalyst and ensured the effective access of reactants to catalytic active centers in water.Additionally,the Pd@NHCS-600 catalyst exhibited excellent catalytic stability and broad substrate applicability for the selective aqueous phase HDO of various biomass-derived carbonyl compounds.The proposed surface microenvironment modulation strategy will provide a new consideration for the rational design of high-performance nitrogen-doped carbon-supported metal catalysts for catalytic biomass transformation.催化加氢脱氧(HDO)是实现生物质基含氧化合物增值催化转化的关键途径.开发高效和高选择性的负载型金属催化剂对生物质基香草醛的水相HDO制备高附加值生物燃料至关重要.负载型金属催化剂的表面微环境(活性金属中心的电子结构和载体的性质)决定了催化剂的加氢脱氧性能.除活性金属中心的电子性质在调控催化HDO性能的主导作用外,载体表面润湿性也会影响催化剂在香草醛水相HDO合成2-甲氧基-4-甲基苯酚(MMP)反应中的活性和选择性.现已报道金属催化体系难以实现活性金属中心电子性质和载体表面润湿性的协同调控,致使催化剂水相HDO性能还有很大提升空间.此外,高温高压苛刻的反应条件对金属催化剂的稳定性和产物选择性造成巨大挑战.本文以氮掺杂中空碳球(NHCS)负载Pd纳米反应器作为香草醛HDO催化剂,通过合理调控中空纳米反应器的组成和结构,精确剪裁金属催化剂的表面微环境以提高其催化HDO性能.本文制备的氮掺杂中空碳球载体的化学组成和多孔结构对金属催化剂表面微环境影响显著.NHCS中N原子的引入,一方面能诱导产生电子金属-载体相互作用(EMSI),调控活性金属的d带中心以提高催化HDO活性和选择性,另一方面,还能赋予催化剂表面良好的亲水性,促进催化剂在水溶剂中均匀分散,加快反应物对催化活性中心的接触.本文采用二氧化硅硬模板导向的多巴胺和Pd前驱体的聚合和碳化过程,研制出一系列氮掺杂中空碳球负载Pd催化剂(Pd@NHCS).研究发现,催化剂前驱体焙烧温度对Pd@NHCS的表面微环境包括活性Pd中心的电子性质和NHCS载体的润湿性和多孔结构影响显著.该系列催化剂在香草醛水相HDO反应中表现出优异的催化性能.其中,Pd@NHCS-600催化剂在120°C,0.1 MPa H_(2)的水相温和反应条件下实现了香草醛向MMP的100%选择性转化.催化本征动力学测试证明了Pd@NHCS-

关 键 词：Microenvironment modulation Nitrogen-doped hollow carbon sphere Pd-based catalyst Electronic metal-support interaction HYDRODEOXYGENATION VANILLIN 

分 类 号：O643.3[理学—物理化学]