Chinese Journal of Catalysis ›› 2025, Vol. 71: 267-284.DOI: 10.1016/S1872-2067(24)60261-5

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

Jun Wua,*(), Liqian Liua, Xinyue Yana, Gang Pana, Jiahao Baia, Chengbing Wanga, Fuwei Lib,*(), Yong Lia,*()   

  1. aSchool 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
    bSchool of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2024-12-03 Accepted:2025-02-08 Online:2025-04-18 Published:2025-04-13
  • Contact: * E-mail: wjhg168@163.com (J. Wu), fuweili@ucas.ac.cn (F. Li), yongli@sust.edu.cn (Y. Li).
  • Supported by:
    National Natural Science Foundation of China(21902094);National Natural Science Foundation of China(22472177);Natural Science Foundation of Shaanxi Province(2023-JC-QN-0103);China Postdoctoral Science Foundation(2020M683405);Scientific Research Program of Shaanxi Provincial Education Department(23JK0344)

Abstract:

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.

Key words: Microenvironment modulation, Nitrogen-doped hollow carbon sphere, Pd-based catalyst, Electronic metal-support interaction, Hydrodeoxygenation, Vanillin